===============================================================================
Hagerman Technology WebLog, 2005
===============================================================================
December 24, 2005
-----------------
Part came in for BUGLE2. This is one very compact board. Even the chassis box
is small. Looking good so far, except the electrolytics are too tall. Will
have to change to another part. Everything mounted on board, except LED wires.
This should make it easy to build. Slips right into chassis.
BUGLE2
Been swamped with Christmas orders. Trying to get ahead on the woodworking
curve. The Trumpet panels take a LOT of time. Been running my CNC
continuously for days now. Had to borrow a computer from the office to run it,
as the previous 3 computers in my shop have died. I think the trick is to
never turn them off. Anyway, I mentioned below I was looking for an old 486
sitting on the side of the road. Well, time is money, so took a look at eBay.
Holy cow! I can't believe the decent laptops you can score for $100. Just a
few years old, too. So I picked out a mint Toshiba (like the one I already
had). Price shipped to HI only $93. This will actually save me effort and
time. Will dedicate the computer to my CNC.
And then I remembered the way cool iMac Mini for $500. Which is actually
$1300 when you add a display, keyboard, and mouse! So I eBayed that. Found
the older iMacs are yard sales. There are a TON of the original iMacs out there
for $100 to $200 complete. With DVD. Ok, they're CRT types, and old school,
but what a cheap transport! Could be the cheapest option available for a
music server. Hope they don't have a fan. I think I'll do this to start a
dedicated music machine. Eventually, I want to record too.
December 19, 2005
-----------------
Got my BUGLE2 boards in. They look cool, so incredibly small. Forgot to buy
parts, will have to wait to stuff it. Been very busy filling Christmas orders.
Good news, the power supply boards came in early. They go out tomorrow.
Trouble in the lab. Another computer died. This is the third computer I've
had attached to the CNC milling machine to crap out. Damn software only runs
under DOS, so my laptop can't handle the job. Running DOS off a floppy! Gets
the job done. Had some Trumpet woodworking to do. More good news, a computer
that can run DOS is basically free - you'll find them on the sidewalk or trash
bin everywhere. We'll see how long this takes.
December 13, 2005
-----------------
Working hard on this compressor. Need a name for it. Starting to look ok,
really hard to place controls, as the circuit board is packed. I have the
controls and circuit all on one board, parts on both sides. Nice tube circuit,
trannys on both input and output. Power supply section similar to CLARINET
series. Side chain circuit mostly complete, a few details to go. Trying to
add useful functions, like hard and soft compression modes, ability to link
channels (and other compressors), instrument input (guitar), and full
adjustments for everything. I did get rid of the threshold control (I don't
like sharp-knee operation) and secondary gain. VU meters are LED, since I
think the faster response is important for digital recording. The layout is
folded back on itself in order to keep the tubes and I/O connectors away from
the power supply. The side chain is then on the right side. Anyway, good
progress.
Compressor
Meanwhile, Bas Horneman's second issue of DIYMAG came out. With me on the
cover! Interview on page 23.
DIYMAG
December 11, 2005
-----------------
What am I doing? Just ran out of power supply boards (on re-order), and
realized I have a TON of BUGLE boards left. Why in the heck would I introduce
a BUGLE2 when I have so much in stock. Not too brilliant. Of course, I will
sell both, BUGLE will become BUGLE CLASSIC. Did I just shoot myself in the
foot?
Spent time analyzing various compressor topologies. Wow, there are so many
ways to go. I'm not worried about the tube circuits at all, I know that is a
slam dunk. It's the side chain. Easy to do opamp and transistor circuitry,
but it is the architecture that counts. I really like some of the tricks done
with the LA2A. Very clever, not obvious. One thing I don't like with most
compressors is that they have both input and output gain controls. Is this
necessary? What happens is that the amount of compression is relative to the
input gain. The output gain is just to make things back up to line level.
Well, why do that? Why not make compression relative to output level? I think
this might make usage easier. Set the amount of compression you want, then
dial in the gain for a 0dBV output level. Heck, I'm sure the output of
compressor goes to a mixer somewhere, which handles the relative volume. Why
not remove one of these gain controls in the chain? Should be easier to use.
My other trick is to have sidchain track this, so compression setting is always
relative to 0dBV output. No matter what your mic input level is. Then I can
have both hard (like the LA2A) and soft compression modes. My other trick is
to use my gamma circuit (patent #5,461,430) to correct the non-linearity of
the vactrol. I can much better control compression level, make it really soft.
Also, came up with a really simple linear ramp attack & release circuit using
my favorite LM13700 chip. Very few parts, glitch-free operation. The concept
for mechanics is unique, one circuit board with controls on one side, tubes on
other side (soft of like CORNET), mounts right onto rack panel. Back panel
mounts to other side of board. Very thin sandwich. No wires. Imagine
building a tube mic preamp & compressor with no wires. Except maybe from the
power tranny. Not sure I can fit it into a 2U space, probably go with 3U.
December 7, 2005
----------------
Yeah, I'm not working on what I should be. Finished BUGLE2 schematic yesterday
and did layout today. Pretty darn tight. I got the entire bugle circuit, the
power supply, and the hagclock regulators all on a board smaller than the
original bugle. Most of it looks great, but I worry about the closeness of the
transformer. It's darn near the phono section. Toroidal, and I have some heat
sinks for shields. We'll see. Worth a try, as this board fits into a very
small chassis.
BUGLE2 layout
December 6, 2005
----------------
I can't stand it, this is so much fun designing a tube compressor. I guess it
is just something I always wanted to do. Similar to a phono stage, but with a
solid-state sidechain. Came up with some neat implementation for the attack &
release circuit, different twist on gain control. Actually, a very difficult
machine to design. So much to think about with interactions. Probably do a
stereo version, as it is more tube efficient. Have a new construction concept
that is cool and low cost. I think this will make a great half-kit. We'll see
how things progress. Could be a great introduction into the recording market.
Meanwhile, some consulting work has dried up. Darn, that was gonna pay for a
lot of the R&D I have planned. HAGUSB taking off, so maybe it's no big deal.
With this extra time, maybe I can do the long-awaited BUGLE2. Ok, so I just
thought of it. People have been asking for a box to go with the Bugle for a
long time. Thinking a BUGLE2 will keep the super-low cost structure, but add
minimal features, like a box and ac power supply built-in. I'll even add the
super regulators from the HAGCLOCK. Still minimalist, no power switch or LED.
But no wall wart, either. For $100 you can build one superb and competitive
stage, without having to worry about batteries. Easy to build, no wires.
Love to design. Always putting off those chores I should be doing. Got
clients waiting.
November 30, 2005
-----------------
Finally got the DISCMASTER wired up. And it works! A neat idea, would make a
fine DIY article. Except for the fact I just ambushed it by cancelling the
JIMDAC project. Sure, a HAGDAC will fit, but I don't sell that as a half-kit.
Hmmm, what to do? I have one box, guess I can sell it. Maybe do a local road
show. The BUGLE gets really small when you chop the battery wings off.
DISCMASTER frontDISCMASTER back
November 28, 2005
-----------------
Deciding not to do the JIMDAC. I think it would be a cash drain. Great
implementation of a popular circuit (yet different in many ways), but it seems
just way too hard to scrounge up the necessary chips. So here's what I'm going
to do, give away my last remaining JIMDAC board. The layout happened to be
perfect with no mistakes (a rarity for me), so it will be easy to build. The
other one will go into the DISCMASTER, which I will probably sell. Will post a
contest on my circle. Best logo artwork will win for xmas.
Added a search box on my home page. Not sure how useful it is, but might help
speed things up for some. Type in "snubber", see what comes up. Returns only
hits from my site. Uses Google engine, thanks!
Finished my interview for the new german diy web magazine with Bas. Doc was
the first. That puts me in great company. I'm very honored he asked!
DIYaudioMAG
Yet another web-only audio mage got off the ground. This time from
Jeff Dorgay.
ToneAudio
Thinking a lot about my next line of audio gear. Wondering if I can include a
microphone preamp/compressor. Sounds way out of line? Maybe. It is something
I always wanted to do, like the phonostage. Looks like I could sell a ton of
half-kits. Get the impression home studio/recording is just as big an industry
as hifi. Maybe guitar DIY even bigger. So I thought, hell, maybe I try out a
half-kit and see how it does. Then, maybe I can do a machine to match the new
gear. Design it to play right into the hands of my "tape loop". I can't think
of any hifi'ers who are interested in mic inputs. Let alone expensive ones.
But maybe some studios would be. All differential tube stages feeding the best
of digital (the part they already have). I'm guessing there will be a little
crossover market between ultra hi-end and studios. Both connoiseur mentality,
demanding the very best. And here's a twist (I told you I might give too much
away), the machines will have serial ports to talk to a PC. A Windows or Mac
program would then be able to control the machines directly, all under software
control. Maybe handy for a studio, or the next generation of home theatres.
November 23, 2005
-----------------
Well those TDA1543 from Singapore finally arrived after a month in transit.
Plugged one in to the JIMDAC, and voila! Music. I had everything else
debugged already. Sound was pretty decent, but I could tell right away it
didn't hold a candle to the HagDac. And I'm able to do a pretty good
comparison, swapping boards onto the same motherboard. Same everything, swap
DACs. I have gain set a little low, and there was some minor dc offset (easy
to fix). But there is one major flaw, the inductors I used were bobbin types,
they picked up buzz from the nearby power transformer. Need to switch to
shielded cores. At this point, I can't tell what all the fuss is about. It
doesn't sound that spectacular. So I went to measurement mode.
JIMDAC scope measurements
The 1kHz had numerous traces (fuzz). Each time it swept past it was on a
different path. I zoomed in on the edge so you can see this. The 20kHz sine
was as expected. Aliasing to the max. Some folks say you can't hear this.
Maybe a brick wall filter will get rid of this. But who wants that?
At this point I am no longer excited about selling JIMDACs. It's nearly
impossible to get parts for it, the measurements suck, and it gets smoked by
the HagDac. I'm not sure I want to bury any more time into this. Was very
happy with the implementation, circuit and layout. But what's the point? I
can't come up with a good reason to sell a me-too DAC.
November 10, 2005
-----------------
So whaddayaknow, I won a "blue note award" from EnjoyTheMusic, best of 2005 for
the UFO. Kinda funny, as I've sold maybe ten of them. But hey, it was a
brilliant flash of inspiration, that the LEDs did not have to stand still.
Making a one-piece strobe is pure innovation and something new to the world.
The problem is, it's ugly as heck, and nobody wants to spend the time to make a
DIY clamp housing for it. So good idea, terrible execution.
Blue note award
Sales really taking off these past few months. I can't explain it. Wondering
where I fit in now compared to other manufacturer's offerings. Looking at the
ETM contest page, I see the price/performance of my machines is still very
competitive. For the same price, you can get a lot less machine.
ETM contest
Then I think about the CHIME. The only other USB tube DAC I see is the BRICK.
For the same price, you can get a wall-wart, no reclocking, 16-bit conversion
(instead of 24), and no output filter. Compare the guts of these two machines.
I am comforted that the CHIME is an absolute high-end steal. Although I bet
the BRICK outsells the CHIME 10 to 1.
Brick DAC
BTW, I'm still waiting for the dang TDA1543s to show up. Would love to get
this JIMDAC online.
November 5, 2005
----------------
I don't know what happened to the TDA1543s I ordered from some online web store.
Supposedly shipped two weeks ago, haven't seen them. Still, I am anxious to
get JIMDAC off the ground. So I bought three of these chips from an eBay
auction. All the way from UK! Wonder which will shoe up first. Makes me
wonder why I see so many DIY DACs using these same parts. Why? They are so
dang hard to find. I had to bust apart and old Parasound DAC for the Crystal
chip. Web for others. Are there enough chips out there to even bother with
trying to sell a JIMDAC? I get the feeling most potential buyers will want me
to solve that problem ahead of time. I'd hate to guess wrong and buy a big
pile of boards nobody buys. Been there, done that (UFO, OBOE).
Reconsidering selling the HAGDAC as a half-kit. Sold two test cases to see how
it goes. Very difficult to put together. But hey, if that's what you guys
want, it's my job to make you happy. If things work out ok, then I'll include
the non-DigiKey parts in the deal (VCXO, receiver, phase detector). Probably
sell for $129.
October 31, 2005
----------------
This will be my last daily post. For awhile. I'll try to update blog on a
weekly basis. Doing way too much non-audio consulting right now to keep things
interesting. Kit sales are doing quite well, but it's not enough to make a
living from. So I am forced to make up the difference by taking on other jobs.
Just got wrapped up in two very big, somewhat long-term contracts, so new kits
will be on hold for awhile. For me, it is a good time, as I am shifting the
focus of my business. Or more accurately, I am starting a new company called
Hagerman Audio Labs - an upmarket spinoff from Hagtech. I've accomplished what
I set out to do with Hagtech. Built the company, infrastructure, reputation,
customer base, and a full product line. After VSAC2003, I was very excited to
start the design of the "C" series. That is now complete. The family of
Cornet2, Clarinet, Cymbal, and Chime are the ultimate in DIY for value. There
are a number of new kits I'd like to design, but realize the ROI is not always
positive. Hagtech is not going away. I will continue to offer new product,
but at a much slower pace. Most of my attention will be focused on product
development at Hagerman Audio Labs and customer service.
I've already worked out conceptual products for Haglabs. First out will be a
set of three machines: analog, digital, and power. The 'analog' will be a
linestage with built-in phono section, 'digital' a DAC and ADC processor, and
'power' a big 300B or similar amplifier. All circuits will build upon the
balanced circuits developed for the Trumpet. All components super-high-end, no
compromises anywhere. I guess you could call these statement products. And I
came up with this way cool 2-button remote control (it will be widely copied).
Could give you a lot more exciting details, but don't want to give away the
store. Wait until you see how I do the attenuators! Not going to be cheap,
assembled only. Will keep you posted. Oh yeah, also thinking about a studio
series starting with a mic-pre-compressor.
On another note, finally hit the podium at last triathlon of the year. This
was my last chance and I did it. Took 2nd place in age group. Had a good bike
segment, managed a loop average of 22mph. I was 2/15 for 45-49 year olds. Top
12% overall.
Tri Results
October 27, 2005
----------------
Here's another good one:
"The only valid market survey is ... a signed purchase order".
How true that is. I remember when I first got started in this business, Allen
Wright (of fame) told me basically the same thing. Think he even took orders
for his preamp cookbook before he even wrote it! I was one of them. Market
research is hard. The best is when customers vote with their wallets. In
fact, this is similar to the DARPA concept of gambling on terrorism. Superbly
clever and accurate if done right. When people put their money where their
mouth is, the results are far more accurate.
So it gives me an idea. How about I offer a 50% discount on a future product
if you pay 20% now? Is that wierd, or what? You will find out up front if the
idea is valid or not. It answers the question before you even build it! It
also gives you some up front capital. If the response is anemic, then you
refund the amount and cancel the project before you waste time or money. Hmmm.
October 26, 2005
----------------
Cleaning out some old files, came across this sketch of the Trumpet. Actually,
the name originaly was Achez ("H's"), with an upside-down e. Meaning "H" for
the shape of the frame, shape of anti-vibration suspension viewed from side,
the shape of the long-tailed differential pairs when drawn, and for Hagtech.
ACHEZ sketch
First prototype had dual volume controls.
ACHEZ proto
And whatever happened to the CLARION? It was my attempt at a stereo SET using
either 300B or 2A3. Design got held up because my ultrasonic sinewave heater
circuit didn't work. I do have an idea on a replacement. Maybe someday I can
get back to this.
CLARION
Here's a test I did of gm versus heater voltage. Forget what tube it was,
probably a 12AX7. Measurement done using a VacuTrace. Also plate resistance.
gm vs. Vhrp vs. Vh
How about the "half-kit" logo I made but never used?
Kit/2
And I once solde the VacuTrace as a kit. What a nightmare! Only sold one.
VacuTrace kit
October 25, 2005
----------------
Solved. Can just use the next phono jack in the same series - a 4-pin version.
Just cut off the 4th terminal to fit in board. CP-3554NG-ND.
Ran across another wise quote. More of a paragraph, actually. I am often
moved by wisdom in print. Give me reason, sense, perspective, and facts. Then
offer an opinion. This snippet is from PC Mag:
"There was this tremendous bureaucratic organization where trivial decisions
took an infinite amount of paper work. That's expensive. Plus, it makes it
very difficult to reverse decisions. The more people invest in decisions, the
more they cling to them. All you need is for people to cling to a couple of
bad decisions and you're dead."
October 24, 2005
----------------
What a busy weekend. Two 4 year old birthdays and one kindergarten class
picnic. Oh, what to do with my FRYBABY. Have completely designed and debugged
this new product. Was going to sell it via OEM, but they're like a black hole.
Hate to waste all this time and cash investment.
Meanwhile, discover the phono jack I picked for the HagUsb is no longer stocked
by DigiKey! Holy crap. Why does this always happen to me? This is not the
first time, either. I thought I learned and make sure I check stocks during
design development to make sure this won't happen. Must have slipped through.
Now I need to find a plug compatible replacement. And right after I invested
in a hundred circuit boards.
October 20, 2005
----------------
So who is www.prodigy-pro.com? Checked out my web stats again, found this
place was giving me 2.7% link referrals. Hmmm. So I went there and found they
have a forum very much like audiocircle. Must browse it sometime, looks like
pro recording and guitar related stuff. Somebody mentioned a Bugle, that's
where the hits came from. Not sure I'm going to renew my PFO banner. Giving
me presently 0.5% of total page hits. Either it's not worth the cost or my
banner sucks. Then I'm getting errors on people trying to link to robot.txt.
What the heck is that? Is it something that webcrawlers look for?
Where are the TDA1543's I ordered? Dying to get my JIMDAC online.
Meanwhile, I'm selling a bunch of FryKleaner Pros. When it rains, it pours.
Must have been a good online review somewhere. Seems I always get batches of
orders when such occurs.
October 19, 2005
----------------
Overloaded with consulting right now. Still waiting for my regular TDA1543's
to show up. Running out of parts for iRIAA. I must average two part shipments
every week. Hard to stay on top of inventory.
Anyway, thinking a lot lately about next generation products. Been reading pro
recording magazines to get a feel for that market. I also want to expand the
capability of the next linestage or DAC by including an ADC. Why not add the
ability to rip high quality two channel to CD or DVDA? Trying to figure out
what people would actually use. Just 44.1k or 96k and 192k too? I think the
24 bit stuff to computer would be really cool. Machine should do both digital
playback and record. So far, I don't see this in the high end. But plenty of
players in the pro market. M-Audio has some way cool machines. Question is,
how to do this for the exotica high-end? I think the USB input on CHIME is a
great first step.
So where does the ADC go? In the linestage? I think it makes sense to put it
in a digital processor (DAC) box. But the volume control in the linestage is
perfect for trimming levels. Probably should get both boxes to work together
as one. I plan on a way cool remote control, hence a CPU in each box. So do I
run some sort of communication bus between boxes? I'd rather not. And then
do I use the high-gain stage in the DAC output as an alternate mic input amp?
Nah. Going in a lot of circles here. Trying to work out an I/O topology that
uses circuits wisely and has a simple, effective human interface.
October 17, 2005
----------------
Painted all weekend. Still at it. Nothing to report. Just consulting and
shipping products. Painting.
October 13, 2005
----------------
Added EnjoyTheMusic contest logo to website home page. This could be a very
effective method of advertising. For the cost of a phono stage, I get my logo
printed in a number of places, including inside cover of T.H.E show brochure in
Vegas. I remember Thom mentioned a similar idea last year - an coop of small
manufacturers pooling resources together to buy ad space. Difficult with
issues of cost sharing, leadership, etc. Well heck, the ETM contest
effectively accomplishes the same goal, but with a capitalist twist. We each
decide how much to spend. Space given accordingly. No issues of shared
ownership or responsibilities. And the lure of free prizes! I think a LOT of
people are going to sign up.
Been also thinking about utilizing space on my website more effectively. Can
put banner ads all across the top, or down the left side under the menu. Maybe
I can swap links at little or no cost. Sometimes the ads are annoying and just
add clutter. But maybe it can be reasonably done without too much intrusion.
I think they can offer added value. Good, appropriate links can help. Also,
reverse links to hagtech help push me up higher on google searches. Suprised
how important this is. I get more referrals from google than anywhere else by
far. Anyway, the site needs a redesign. Starting to look dated. Vintage, in
fact.
Did chassis work for DISCMASTER. Mounted boards. Looks pretty cool, I think
this will be a fun and useful DIY project. I applied the labels a little
crooked, but hey, it's just a proto. Work out the bugs now so you don't have
to. Once I get the DAC chips in for JIMDAC, can test it out and prove design.
Then I will mount it in here. Should make for a good audioXpress type article.
Except that it's a little blatant in that you need to buy my boards. Cutting
the Bugle board down to size solved the fit issues.
DISCMASTER
October 12, 2005
----------------
Have to return the TDA1543A parts. Something about 2's complement versus
whatever the Japanese spec is. Otherwise, the timing of mode 5 would have been
ok. Bought a pair of regular TDA1543 parts online. Forget what store. Does
not seem to be many places out there to buy this chip from. Anyway, it means
that proto layout is perfect. Not one glitch. That is pretty rare for me. Of
course, for production I will add pads for SO-28 and a reset circuit just in
case. Works without one, but I prefer to be safe with these issues.
Anyone seen the latest TAS? Chinese invasion. Oh my, everywhere I look now
there is a new brand of amplifier. Fortunately, they are all knockoffs of
classic circuits (pentodes with feedback) and offer nothing in terms of
innovation. But hey, they look great! No idea how the sound is, yet the
chassis work and detail is tremendous. Very clever. One of them even brags
about being an aircraft manufacturer! Has anyone ever been on a chinese
airliner? This is good for me. They are focusing on metalwork, not circuits.
The emille brand is a total ripoff of a VAC amp. Superb-looking casework. The
VAC folks must be pissed. One of the brands I saw comes with two names! Two
product lines, only change is the faceplate. That's why I also think the Prima
Luna line comes from ASL. Who else on this planet puts the power switch on the
side like that? So will the marketing work? Or will there be a glut of used
amps for sale next year? I think some of it is brilliant. Sell the amps
cheap, make the profit when they come back for tubes! Genius. Sort of like
video games. Am I jealous? Heck yeah. I spent years focusing on circuits,
sonics, innovation, performance. Why? Could have made a ton more money if I
just had a thicker faceplate with cables the size of a garden hose.
Sending a Cornet2 off to the European Triode Fesitval. They're doing a
shootout of phonostages. Mostly home-brew, commercial units tend to shy away
from mano-a-mano comparisons. I figure what the heck. With these exchange
rates, the half-kit is a steal. Rather send a Trumpet, but the Cornet should
hold it's own pretty well.
Ugh. Just discovered I wired the volume pot backwards on the CHIME. Sheet.
Now left is right, right is left. Ok, so you have to swap cables. I don't
understand why I always have a problem with the simplest things. It's like
I'm dyslexic. Not with order or sequence, but with inversion.
Oh, and about my comments regarding chinese amps, before you think I'm just a
racist haole, take a closer look at my family. Really, I'm just calling it as
I see it. New low-cost producer invading the industry, that's all. Happens
all the time. Could be anyone.
HAGFAM
October 10, 2005
----------------
Fired up the JIMDAC. Everything looks right, but just getting noise on output.
Seems data is using wrong format or something. I think I have it in mode 2,
I2S. Then added reset circuit for receiver, that made no difference. Supplies
and input are perfect. Receiver locks, everything clean. Can't find the
problem. Tried both USB and S/PDIF inputs. Using that DACPRO board I made as
a test bed. Makes debugging this and the HAGDAC real easy. So close. Could
be something is lost in the translation to +/-2.5V supplies. Come to think of
it, why do I even have the +5V? Wish I had more time to spend on this, so much
consulting stuff going on right now.
An alert reader notified me the CS8414 is pin compatible with the CS8412. So I
think my strategy will be to put pads for the surface mount package inside the
DIP version, board can be used with either. Like the TDA1543, I'll buy up a
batch to make these available at reasonable cost. Then everything else is
available from DigiKey.
Aha! I must be brain dead. Remembered why I have separate 5V supply, to keep
digital and analog somewhat separated. And a bit of research discovered that I
am using the TDA1543A version, which is completely incompatible. Found a note
that suggested using mode 5 on receiver, but that didn't work much better. So
now I have a rack of useless chips. Will see if I can trade them in. Good
news is that I am not insane. But now we have yet another delay in getting
JIMDAC off the ground. Had actually built an all 5V version just to make sure
it wasn't anything funny electrically.
October 7, 2005
---------------
Updated the link below with a finished JIMDAC. Wow, looks really good. Never
had time to power it up. Maybe this weekend (yeah sure, as soon as I finish
painting the bedroom). Putting new feet on my Horns. We'll see what they
sound like with some stuffing. Going to change the Fostex mounting screws to
nonmagnetic brass. Offering up a Cornet2 as a giveaway prize at the upcoming
EnjoyTheMusic raffle. Lot's of companies giving away stuff. Check it out in a
week or so and sign up. You may win an amp, or some cables! I think it'll be
big. So I asked Steve, can I send you a HagUsb to play with? Sure, he said.
So I sent him one. But Doh! So busy with the over-multi-tasking I forgot to
test it out first. Holy shiese, talk about egg on my face if that baby don't
power up.
October 6, 2005
---------------
God was looking down on me favorably today - Stu found a chip! Yes. Can't
wait to fire this baby up. Now waiting for box from DigiKey. Then debug one
piece at a time. First regulators, then front end, receiver, DAC, and output
buffer in that order. Always go to populate board as you go, you never know
where the short or smoke might occur.
JIMDAC
Realized it takes me a lot of assembly and test time to make the HagUsb. Gotta
fire up the CNC to mill out end pieces, build board, make sure it all fits.
Then fire up the laptop to check out both headphone and S/PDIF outpus. Easy
stuff, but timewise adds up. That $129 retail price is seeming awfully low to
me now. Thinking after a decent introductory period I'll have to raise it to
$159, in line with the Bugle. Very happy with the way it came out. Found
these new laser labels made from plastic that are very rugged with a matte
finish. Product looks very professional, not hand built.
An astute customer sent me this quote today. Regards business development,
advertising. All that other stuff we've been talking about.
"The art of business requires the intuitive ability to grasp the essence of
a unique market situation, the creative ability to devise a practical solution,
and the strength of purpose and skill to execute the act."
October 4, 2005
---------------
JIMDAC boards came in. I should have parts any day now, will post a photo.
Still trying to get ahold of a CS8412 DIP. I'll trade any $39 half-kit for
one. Or heck, I'll pay $39 for a working chip. Lemme know if you have one!
Made a new ad today. Actually, Dave did all the real work. Always thought
this type of ad was rather effective. The Avante-Garde guy uses these a lot.
Think I'll post in a January issue, where they are often given away at CES.
New 1/3rd page ad
October 3, 2005
---------------
Newspaper article suggested using newsletters as a business marketing tool. I
see other companies doing this, but rather ineffectively. Adding discount
coupons is nice, though it helps to add tips or answers to common questions.
Gotta offer something of value or interest. Should have some useful content
other than just 'look at me'. I could do this, having compiled a huge database
of email addresses. Doesn't seem right, though, to spam. Nobody signed up for
a newsletter. Thinking the audiocircle forum is a much better place for such
information and advertising. So I won't do it. I personally revile spam.
Still haven't come up with a single CS8412 chip for testing JIMDAC. Sheesh. I
really want to hear this proto. Boards should arrive this afternoon.
Lab move presently on hold. Too busy getting old carpet ripped out and wood
floors installed in the house. Sheetload of furniture and stuff to move. One
room at a time. Agonizing. And then there's the dust! Lab has to wait until
I get this done first. Still, I look forward to reorganizing the shop and
sorting inventory. It's been out of hand for the past 3 years. I've got parts
all over the place.
Checked out the website hits. Averaging about 1000 per day. Not bad for such
a small company. You find some odd things, seems my pdf files on various
technical topics get hit a lot. Especially the snubber one. Dug deeper and
found a lot of my stuff is being referenced from discover circuits, a site
dedicated to surfing and indexing the net for useful circuits. I get a lot of
referrals from this place.
DiscoverCircuits
September 30, 2005
------------------
HAGUSB production boards in stock. Will ship out all pre-orders today.
Thanks! I think this will be a big seller. Nice board, very compact and
useful. JIMDAC boards just shipped. What was I thinking? There are no more
CS8412 DIPs left on this planet. Stupid to design it in. Hopefully Stu can
come through for me and find an old DAC in his shop. Will probably redesign
to use the same CS8415A as the HAGDAC. That way I don't have to stock too
many different parts. Purchased a big batch of TDA1543s. Will offer these
cheap to go with JIMDAC. That way all other parts available cheap directly
from DigiKey. Should be a honey of a nice cheap DAC. Started building the
DISCMASTER, which the first JIMDAC will reside in.
Regarding the comments from yesterday, don't think I am whining. It is merely
my realiziation of marketing, as I see it. Not good or bad. Just different
markets and different customers. It's all about understanding where hagtech
fits in, and how I can do better to provide products and services that are not
irrelevant. Do I think some of it is rabid excess? Greed? Heck yeah. But it
seems to fit a market need. And that is what is important.
September 29, 2005
------------------
The CHIME across america tour starts today! Will be sending out a CHIME and
CLARINET and HAGUSB on a daisy chain tour of reviewers. AudioCircle folks got
this started as a low cost way to generate some product interest - that is, if
they actually sound good.
I like to read a lot of audio magazines. Hey, it's a hobby. And also to keep
abreast of the industry and competition. Sometimes I just bristle at what I
see. This relates to the marketing stuff I brought up previously. So many
companies got this sales game worked out, often to the detriment of the
consumer. Make a nice, heavy, fancy box. That's all it takes to sell. Put a
couple of opamps in it. Here's an example:
Preamp example #1
Or for three grand, you get 23 pounds of chassis, a couple of jfets, and a $12
transformer. Parts quality is good, maybe it sounds wonderful. But it proves
the new game is weight. The heavier the machine, the better is must be (even
if hollow inside). Sort of like cable manufacturers playing the diameter game.
Do I really want a power cord thicker than my wrist?
Preamp example #2
Then there's the path maybe I should have taken. The all-tube handcrafted no
feedback linestage. Oh wait, I did that (CLARINET). Just forgot to charge
twenty grand for it. Maybe it's all in the faceplate? Here'a a wonderful
example:
Preamp example #3
I guess there is market space for everyone. Some more profitable than others.
Glad to find an example of a company that is trying really hard. This chassis
is stuffed full of good parts, and it sells at a price low enough to ward off
Chinese imports. I'm impressed, these guys are really putting in the effort:
Preamp axample #4
September 27, 2005
------------------
Holy cow, the going rate for CS8412 is now $28.25! That puts the kabash on my
plan to offer DIP-only for JIMDAC. Sheesh, no way are we gonna pay that. All
sources have essentially dried up. Have to come up with plan B. Think we're
stuck with a surface mount part, folks.
And what's up with the FRYBABY? I better fond out if the distributor is
bailing on me.
September 26, 2005
------------------
Wow, had no idea the CS8412 are so hard to come by. Might have to order a
stash. I really want to stick with DIPs for the JIMDAC. Surface mount is just
wrong for most DIYers. And I want to bring top-notch circuitry to the masses.
So I get this idea for a big DIY project - the FRONT-END. Ok, it needs a
better name. Everyone suggests I do a nice looking chassis for the Bugle. It
is such a giant killer, may as well make it look like one too. But why stop
there? How about adding a DAC to make it a full-blown DIY front end? A combo
phono/dac with USB input and ac power supply in one box. Ok, not super cheap
once you total it up, but you can build it in pieces. Or make it just a phono
stage. I found a pretty decent box at DigiKey; add a POWER SUPPLY, BUGLE,
HAGUSB, and JIMDAC. You get a lot of stuff in one box. It's not a new
product, but a design article. I'll make a prototype and then write up
instructions with parts lists.
September 23, 2005
------------------
Almost done with JIMDAC layout. Having a heck of a time routing power across
the board using only two layers, with one of them a ground plane. Lots of
supply lines (Vcc, Vee, +5V, +2.5V, -2.5V, +5VA). Making sure I get local
bypassing done right first, plus all critical lines. Working my way out
towards the insigificant traces, one by one. Often you have to go in circles
and rip up a bunch of work to try another path. Takes a long time, but worth
the effort. Barely fit everything on board, the large polyprop filter and
bypass caps for the converter chew up a lot of room.
JIMDAC layout
Locating the CS8412 and TDA1543 is yet another problem. I figured there would
be a few good sources to buy these online cheap. Availability could be real
issue for DIYers. Maybe I'll have to load up on them, sell as parts.
I also see the problem almost every other TDA1543-based DAC makes. Especially
the ones that parallel multiple outputs together. Way too much output
compliance. The part is rated for 25mV, I am pushing it to 50mV (0.05V). Why
are other DACs trying to get 1V or 2V out of it into a resistive load? This is
a serious mistake, which will lead to loads of distortion and even clipping.
Ok, just finished JIMDAC, ordered some proto boards. Added extra holes to make
adding a reclocker nice and easy. Just move one resistor over 1/10th inch.
Easy TTL clocks in and out. Even supply a tap for the super-regulated +5V.
September 21, 2005
------------------
Finished writing a white paper describing the image plane of my new (non-audio)
invention. Will be incorporated into a patent application. Meanwhile, the
lawyer who asked for this additional information sent forms to sign submitting
an incomplete writeup. Yeah, we'll just amend it later, so he can collect more
fees. Ay ay ay.
Finished building the next batch of HAGDACs. Man, those things take a lot of
work. Think I'll do the layout for JIMDAC tomorrow. I don't know why I am so
excited about it. It's really been a fun design so far. Hope I can get
everything to fit on that little card.
September 20, 2005
------------------
JIMDAC design moving along nicely. Way easier the second time through. Using
regulator circuit from HAGCLOCK, other parts from HAGDAC, but with CS8412 and
TDA1543. Using my Bessel filter / I-V converter, set for a rolloff at 20kHz.
That's a linear phase 3rd order design with perfect transient response.
Finished pencil & paper design, CAD schematics all today. Started layout even.
I'm doing the DAC a little differently than everyone else, running +/-2.5V
supplies instead of the norm. This eliminates any output analog level shift.
Better, I think, to do the level shifting on the digital side, even at the cost
of an extra regulator. This is going to be one heck of a nice $39 board. A
perfect starter kit for CHIME, allowing for upgrade to HAGDAC later. Or just
use it standalone, or with a HAGUSB.
JIMDAC
September 19, 2005
------------------
Oops, can't use the TDA1541 because it requires a -15V supply. Checking out a
TDA1543 instead. Now I have to deal with dc offset. Maybe I'll do something
unusual with +/-2.5V supplies.
Meanwhile, someone has entered my house and accused me of theft. Yes, a well-
known and vocal designer (who has contributed much to DIY audio) posted in my
forum that I copied his clock design (in so many words). Holy cow was I
pissed! But let it ride and responded nicely. He couldn't leave it alone and
threw two more punches. Sheesh, do I have to do this? I didn't want to start
a turf war, however, reputation and integrity in this business are extremely
important. So I got nasty. Sorry I had to do this, but you have to stand up
to false accusations or people might start believing them.
Forum accusation
Am I out of line here? If so, please let me know.
September 17, 2005
------------------
So far, 1.05% of my referrals are coming from Positive Feedback Online. Out of
about 6000 page hits. Maybe my add is too wierd. Now I see about 1800 hits
for "favicon.ico", what the heck is that? Oh. Ok, I guess I'll make one.
Had another thought, if the CHIME is too pricey because of HAGDAC, maybe I
should offer a lower cost daughter card? Yeah? I can call this the JIMDAC.
Ironically, to keep it simple, I'll make it non-OS, with minimal filtering.
Yes, I am jumping on the bandwagon! What better way to show the differences
between architectures, than to offer two dacs that plug into CHIME? Not that
I will hold back, I will make this the best CS8412 / TDA1541 board out there,
with super regulators, my discrete receiver, etc. All parts through hole, no
surface mount. DIY only. I suppose $39 plus parts is easier to swallow than
$499. No changes to CHIME.
September 16, 2005
------------------
Finally finished my white paper on why I chose NOT to use 16-bit non-
oversampled conversion in the HAGDAC. It's the small stuff. And I don't want
my amplifier to act as a tone control. That's me, jumping off the bandwagon.
Not 16 bit white paper
September 15, 2005
------------------
Trolling various forums, one keen on PCM1704 converters, etc. These DIYers
want to buy a blank board, not willing to pay the $499 for a top-of-the-line
HAGDAC. So what would a HAGDAC cost if you wanted to do all that surface mount
soldering yourself? Hmmm. $99 for the PCB (no way is all the intellectual
property going any cheaper), plus $50 for a TentLabs VCXO, and about $150 in
other parts, mostly from DigiKey. Trouble is the 74HCT9046A and CS8415A chips.
They're not so easy to get. Anyway, for a lot of trouble, the cost would be
about $300. Not to mention the special soldering equipment you'll need. Is
that worthwhile? I guess for me, it makes a sale where there would not be one
otherwise. Are you really willing to build this? Look closer, it's only 4.4
inches across!
HAGDAC
It is possible I have positioned the HAGDAC and CHIME in a "nowhere man's"
market segment. Too costly for most DIYers (who have a typical budget of $300)
and way too cheap for the boutique status buyers. The people with money want
Ferraris. Which can't possibly cost $1799 (but it does). Perhaps I should
price the assembled version at $6999...
Meanwhile, been writing the white paper on non-OS conversion. Starting
reference design of DAC in a box - a true DIY version built using the HAGUSB,
HAGDAC, and POWER SUPPLY boards. A lower cost non-tube alternative to CHIME.
Similar to my previous DACPRO concept, which has been shelved.
September 14, 2005
------------------
Another DigiKey order. Seems like I put in an order twice weekly. Don't wanna
buy too many PCM1704's at $20 a pop. Trying to get my inventory back in
control, using pseudo-JIT concepts. Really, that just means I'm using up all
the spare parts I've gathered from all of the proto builds, then ordering just
enough to cover the next build. Reducing inventory and debt is key to running
a stable business. Yeah, yeah, yeah, boring.
Paid for a link at PFO. So far, in the first few days we're running at a rate
of about $0.75 per click. Maybe it sounds expensive, but it could prove to
have the greatest ROI of any ad so far.
Just put up the HAGUSB manual online.
HAGUSB manual
September 13, 2005
------------------
Installed that new Google Desktop. What a lifesaver! I suppose the PC is just
catching up with Apple, but who cares? I can finally find old emails quickly.
Searching in Outlook was absolutely agonizing. Recommended.
Ran some simulations tonight, something I rarely do anymore (although I love
PSPICE). Found a neat 6H30 subcircuit on the net, put in into a simple
differential CASTANET stage. My thoughts on balancing (a pot) works fine, but
gain is low. I purposely run this output stage without a driver, since phones
need so little amplitude. I get about 0.25V output. Wondering if that will be
enough. I better make some measurements in the lab. What bothers me is that
this can be converted to a 3W amp if I add the driver stage. Hmmm, simplicity
or functionality. Or can I do both?
September 11, 2005
------------------
Thinking this might be a great time to buy a used SUV. Really, if you want to
save money, it's the way to go. An article in the paper here today calculated
that a super-efficient hybrid won't save you a dime until after you've driven
it for seven years. Hmmm, I wonder how long them batteries last before they
need to be replaced? My small gasoline SUV gets about 125 mpg per person.
During my bike ride today, once I hit the "zone" (a zen-like trance), somehow I
solved the headphone amplifier riddle. It all came to me so clear. I've been
futzing around with various ideas for years, but was never happy. Just could
not use the cathode follower type, output impedance way too high, poor bass.
And the cheap output trannys didn't cut it either. Terrible frequency
response. There is no way to do a cheap tube headphone amp without making
severe compromises. That's just my opinion. The CASTANET had to be great
enough to fit into the CONSTRUCTOR series. I really don't want to do anything
but a full-blown circuit. So anyway, there it was, a CYMBAL-like architecture,
only in a single stage. Maybe even the same high-quality output tranny. It
solves all of my perceived limitations. One tube per channel, differential
input, push/pull output, no feedback, low output impedance. Pretty much a 2W
per channel amplifier, tuned for headphones. Switch between 32 ohm and 600
ohm types using tranny output wiring. Only problem is that it will be
relatively expensive, alas the price for top-notch performance. Nothing cut
rate for me. Probably a little more expensive than a CLARINET to build, thanks
to all of the iron. Estimate assembled price in the region of $1200.
Oh wait, I gotta build one first.
September 10, 2005
------------------
My website seems to be getting quite old. Too many products now, the home page
just scrolls down forever. Then menu is getting too big making it hard to
navigate. Time to start thinking about categories and new menus. The entire
site needs an overhaul and new look. Added the HagUsb today. Can start taking
pre-orders. Boards and assembly manual should be ready in about two or three
weeks. Creating a professional label for case. Should look really nice. I'm
even offering the half-kit at the same price as others in this class (Bugle,
HagClock), even though I pre-install the $6 surface mount chip. Hoping the
discount will boost interest. This is a great product.
HagUsb page
Thought up this wierd idea last night at my daughter's birhday party - the
"birthday candle". As it burns, it plays out the birthday song! No
electronics, batteries, or speakers, just pyrotechnics. Her candle last night
had some sparkles to it which added some sizzle. The thought is to design the
fuel density such that it spits out tones or buzzes that can be programmed
into a melody; a long candle with a linear burn having fuel amplitude or
density or whatever proportional to pitch, just like vinyl. I think the flame
itself can act as the transducer. Millions will sell.
September 9, 2005
-----------------
Dropped off a CHIME at Stu's yesterday. Whoah, the soundstage he had in his
main room was astounding. He was on the phone so I sat down in the chair for
awhile. Unbelievably great sound. I swear the room disappeared. I could see
some Vandersteen's playing (big expensive ones), very neutral, clean. But the
stage was soooo wide I couldn't believe it. Then he comes in and mentions he
dialed in a four-channel surround setup on SACD. Then I see some 2C's for a
back channel off to the side. Without the center speaker to smear things up,
the staging was spectacular.
He also suggested something really cool for a future product. If I do ever
get around to making a FLUGELHORN, it should have a matching DAC. And the
idea was to put an ADC into the DAC. Yes, convert both ways. What a neat
feature to be able to take in a linestage analog feed and digitize it, for
ripping a CD. Could be a very high quality way to capture vinyl or radio or
whatever to CD for archiving. ADC circuitry would have to be just as good as a
HAGDAC.
Got another request for a tube headphone amp today. Maybe I should put this
project back on the list. What to call it? CASTANET (a pair of shells)?
Just a thought. Maybe 5687 driving a tranny.
September 8, 2005
-----------------
I wrote up a "teardown" report today on the CHIME & HAGDAC. It has some nice
pictures in it that sort of tell the whole story. Not very polished text, as I
don't have a whole lot of time or resources to dedicate to marketing. Whipped
it up in about two hours. Nevertheless, the concept is pretty cool and I think
it won't be long before others start to copy it.
CHIME teardown report
UPS man just delivered some more parts (the excitment of my day!). Finished
the HAGUSB, everything fits perfect. Holy cow, the headphone output doesn't
sound that bad. Full bass, decent highs, didn't fatigue me right away. Only
16-bit conversion, but WAY better than what you'd expect from a PC. Board is
ready to go. I'm ordering production pieces tomorrow. This can go on sale in
about two weeks. And get this, my daughter is borrowing an iBook G4 from
school, so I just plugged the HAGUSB in. No thinking. And it worked! She was
playing some GarageBand tune on headphones.
September 6, 2005
-----------------
Working on some "click-through" banner ads for websites. I think I'll start
with PFO, since they've posted a few reviews already. Is this pay-to-play in
reverse? Really, don't be cynical. Of all the reviews I've gotten, both in
print and online, none were bought, nor did I advertise prior. That's a pretty
good sign for our industry and hobby. But let's not fool anyone, we're both in
business to make a profit. They need content, I need exposure. Yes, it is a
bit symbiotic in that we both give each other what we need. I really don't
see any corruption in high-end audio, as the very competitive free market will
ruthlessly expose any such fraud. Anyway, I thought my add should be a little
sassy, and stick out from the crowd. This could be it:
Web banner ad
September 5, 2005
-----------------
The new review by Positive Feedback is now online! Kevin Kennedy (an audio
designer and EE himself) put the Cymbals, Clarinet, and Cornet through their
paces for several months. Needless to say, I couldn't be more happy with the
results.
PFO review
September 4, 2005
-----------------
Saw a great article in Forbes last night (yes, I read business rags too, my
favorite is Business2.0) about Jolida. You all probably knew this, but I
discovered they are low cost Chinese-built imports. The story talked about the
difficulties in setting up shop in China, about the rampant quality issues and
mindset, and how warranty costs nearly drove them out of business. I take it
the defect and return rate must have been exceedingly high (article claimed
only 5%) to do that much damage. Makes me think of the ASL line, another
budget import. I remember Upscale Audio pushing these hard in their ads (I've
been paying close attention to marketing, and UA is one of the best). And now
they are replaced by Prima Luna. Is it just me, or do these new amps look like
they're designed and built by the same people as ASL?
Anyway, have you ever looked at the workmanship and wiring inside one of a
low-wage amps? Unfreakinbelievable. You gotta take a look, even if you're not
buying.
Meanwhile, our swim race (Waikiki Roughwater) didn't go well. A super-strong
tide current in the wrong direction made them cancel it for the first time
ever. I did swim out to the first buoy just for fun (about 1km). They were
right, the current would have added an hour to our times. Lotta work coming
back in. Probably kharma, as I also got bit in the elbow by a centipede the
other day. It got all swelled up.
September 2, 2005
-----------------
Frantically building up machines. Plenty assembly work to go around. Won't be
long before I'm ordering more parts. Built up a CONDITIONER too. Tweaked my
G-code file to cut out perfect outlets. Produces pretty good results, but my
CNC rig is so small I have to hand hold the piece (finger vise) for almost an
hour. This is a critical piece to the RACK. I doubt I'll ever sell any RACKS,
but it looks cool. And might make for a nice add - 22 vacuum tubes, no
feedback, complete ready-to-go electronics. Just add cables.
Sold all of my old proto HAGUSBs. I'll take that as a good sign.
Thinking of more web content. To sell CHIMEs, of course. Ever see one of
those "teardown" reports in EDN or ELECTRONIC DESIGN? Pretty cool, they
dissect cell phones, set top boxes, game cubes, etc. to see what chips are
inside. Interesting to see how clever and well made some of these machines
are. I'll do the same for CHIME. A white paper on the guts, and explanations
of why certain design choices were made. Maybe even some scope photo shots.
Might also have to include a section on "why not 16-bit non-OS". It's in my
head visually, need to find a way to put it down on paper.
September 1, 2005
-----------------
Mostly consulting today. Writing a technical white paper describing part of
my mass spectrometer invention for patent lawyer. Lots of work going through
all the math again and organizing it logically in print. I really do like the
equation editor tha comes with Word. It does a fine job. Even better is the
equation formatter in MathCad. It's a great program if you have to do any real
scientific math. I never do anything in Excel except for parts lists.
Started to build up a new circuit board. This one is baseband for a 1.5Gbps
microwave radio. Learning how to deal with these unbelievably fast SiGe chips
has been extremely beneficial to my audio design. Techniques for clean 80ps
(yeah, that's 80 picosecond risetime) edges work even better on digital audio.
The HagDac is full of tricks I learned working on high speed communications.
I gave one of them away today at diyaudio.com. What was I thinking...
Board with 2.7Gbps CDR
August 31, 2005
---------------
Got in the new style HAGUSB. They look great, but dangit, I forgot to order
the RCA and headphone jacks I selected for this design. And I just spent a ton
of money at DigiKey yesterday on other production parts. Forgot I needed
these. Can still test. I wonder how the headphone output will sound. I don't
expect too much, as it is built into the fancy USB chip. I'll probably
pre-mount the surface mount chip even for the DIY version. That will make it
slam dunk for everyone to build. Part selection is very good. Best part is
that I designed it to fit into a little plastic box.
HAGUSB proto
Finally catching up on the big pile of work. Dang that feels good. Thom
Mackris of Galibier Turntable fame and I started a project a long time ago to
make the ultimate motor controller. A resistor (believe it or not) broke in
transit, so he never got a working controller. Fixed it today and sent it
back. Hoping he can show it at RMAF05. Very compact and full-featured board.
Low noise regulators (same as HAGDAC), rechargable batteries (inside pod),
built-in charger, and a select switch for 33/45/78. Yes, I can spin that 30
pound platter at 78rpm! Forgot to take a photo.
August 30, 2005
---------------
I imagine many of you are overwhelmed at the moment by the Hurricane. Anything
I have to say is meaningless.
August 29, 2005
---------------
Done! Finally got the CHIME manual written. Just re-did the website to add
both products. Added to order form. We are ready to take orders. Drill guide
is done, decals, assembly photos, etc. Now I can focus on production for
awhile. But not too long, need to make up some ad artwork. As good as they
are, these products do not sell themselves.
One stupid mistake. I shouldn't even admit this. But I got the silk screen
for the CHIME input select backwards. USB should be on the right, not the
left. Crap. Well, it's only on the first few units. Now I gotta pay for a
new silk screen. That's ok, the rest of it is a work of art.
HAGDAC photo
August 26, 2005
---------------
I'm going to need another CD transport. Going to get tired of moving my cd25
between lab and listening room. Should be able to get away with some old piece
of junk in the lab. I can upgrade with a HagClock and new tranny. All I need
is an S/PDIF test signal within reach. Should think of other things I can do
to improve lab work flow. Moving the lab. Not far, just around the corner to
a better space. Agonizing just thinking of all the stuff that has to move. So
many parts, cabinets, etc. Need a better test bench, too.
Hooked up my CHIME directly to amps, bypassing the linestage. Two volume
controls in series just bothered me (you can build CHIME without). I like this
straight line system much better. The volume control is just right so that I
have to really crank it up to max out amplifier. That's good, because minimal
attenuation is the best (least distortion & noise). Sound is a little punchier
too, probably because of fewer interconnections (which have not been cleaned in
awhile in this nasty salt-air). This is the system to have. Just a transport
(could be computer), CHIME, and amplifiers. Minimalist to the max. The sound
is unbelievable. I wonder why I spent all these years doing phono preamps.
CDs aren't so bad afterall. What's up with that? Getting the same openness
and transparency that I get from the best vinyl rig. I swear I could spin 16
bits all day and not miss a thing.
CHIME chassis just arrived, weeks ahead of schedule. Looks like I'll be
shipping the first units by the end of the month for sure! Will add items to
order form this weekend, can start taking orders. Got HAGDAC manual finished
and online. I'm sure you all wanted to take a look at the schematic.
Pictureman sent out tiny little proofs of the last triathlon. They want $25
for a 5x7.
Tinman photo
August 25, 2005
---------------
USB input works perfect. No more screeching from 48kHz data. Locks perfect to
CD (44.1k) output. HAGDAC design is now complete. Testing done. CHIME ended
up with 92dBA SNR for it's analog tube gain stage. Just need to get that darn
manual written and they're for sale. I'm pretty convinced now that a CHIME
will smoke any other kit DAC you can buy. And it will beat out anything else
available under $2k, including the Benchmark.
Don't worry about that 92dB number. It's real. And it is really good. When
you see someone advertising 140dB type SNR numbers, it's just BS. Easy to
fudge numbers so they appear to be great. Pay no attention to the hype. Trust
you ears. Put the DAC into you system and listen to the residual hiss. Only
way to hear any on a CHIME is to crank volume up to max and then put your ear
inches away from the speaker. At normal listening levels, you can't hear
anything. That's a quiet noise floor. I know it's good because I have it in
my system here at home. CHIME into CLARINET (could even be bypassed!) into
CYMBALS. Jet black backgrounds.
August 24, 2005
---------------
Finally got to finish tweaking the HAGDAC. Careful measurements of the PLL
confirmed a nice stable operating point with no overshoot on the transient
response. I love it when calculations actually work. The -3dB point was about
10Hz high, but fine. I didn't want the tracking to drop too low, so put it in
the low bass region. Sure can see the jitter reduction, even on a scope. The
filter error signal is full of tracking noise. A clear sign of jitter removal.
You can see it also when comparing the receiver clock with the PLL clock while
triggering off the xtal in the CD transport. The wideband VCO on the receiver
chip ain't so low noise after all.
Boxed the HAGDAC nicely in the CHIME and went for a test run. Works perfectly.
The LEDs function as intended, the mute works, channels are correct. Got
completely rid of the 120Hz residual buzz I had in the prototype. The output
is super quiet. Need to do some more listening and USB experiments. So far,
all indications are we nailed it. This baby is ready to ship. Took photos
for the manuals. Can start building up stock.
As mentioned yesterday, have to work on a plan for marketing the HAGDAC. A
coherent and well thought out strategy is still missing. Wondering if maybe
I should even OEM the HAGDAC for use in other companies' products. Like
perhaps Modwright. Dan made a great linestage. He could offer a matching DAC?
Found a long lost photo of Hagtech from 1895.
Hagtech circa 1895
August 23, 2005
---------------
Finally realizing I need a full-time marketeer. Someone to make calls all day,
troll forums, push for reviews, make ads, plan strategy, and get customer
feedback. Asked on my forum about where are the best places to advertise. Was
glad to see audioXpress was rated high. I've been advertising there for 5
straight years. Now it's only every 3 months. So I did some research, spent
some time at 6moons.com. Wow, that's a great site! I can't believe how many
reviews they get in. Why am I not in there? Same goes for PFO. I better go
look at enjoythemusic too. I spend every available moment on engineering and
manufacturing that I forget to stay on top of the market. Anyway, thanks for
the responses. They help. I will definately work on getting some more reviews
under way. The HAGDAC will be a winner. Only drawback is the homely, retro
look of the CHIME. Not up to modern audiophile standards. Way too practical.
August 22, 2005
---------------
Consulting madness. Finished a layout for one place. Then wrote some software
for another. Too many balls in the air at once. This was good to get some of
the emergency work completed. Now I can concentrate on HAGDAC testing.
August 19, 2005
---------------
Ok, HAGDAC opamps came in, all built. Looks like I have something to test this
weekend. HADGAC PRO also built up, makes for a really nice test bed. I'm
going to go through every darn signal on the board and make sure they are all
tweaked to perfection. I even do this for the digital signals. Maybe I'll
post some pics, as they look like analog waveforms. Clean, noise-free, glitch-
free edges without ringing or ground bounce. Everything on this board is
treated as an analog signal. Then I mate it to the production CHIME, which has
already been tested. Manuals started. Right on shedule to ship product by
end of August. Only thing late are the production chassis. But that won't
stop half-kit shipments.
Now to get serious about advertising. I bought space in the next World Tube
Directory. That ad should be for VacuTrace ("still the best"). Need ads for
the new "digital revolution", the HagClock, HagUsb, HagDac, and CHIME. Then an
ad for the "rack". Question is, where is the best place to advertise?
August 18, 2005
---------------
What is the matter with me? I have clients from two islands breathing down my
neck to get stuff done. And yet I spent the morning laying out a new HAGUSB.
Instead of getting paid, I choose to blow R&D hours on something that may never
pay for itself. Goes to show you, it's better to have fun. I'll get the other
stuff done, don't worry. But I just had to do this. Once I took the CHIME
restrictions off, the design was much easier to do. The board came out neat
and compact, designed to fit into a nice plastic box. This will be a great DIY
project. I added a headphone output (volume controlled by PC) and an LED.
Kept the same great transformer output galvanic isolation for S/PDIF. Use it
to add USB capability to your existing DAC. Or as a small headphone driver for
your PC.
HAGUSB layout
This is so cool. I'm looking at my daughters sitting around the living room
listening to vinyl. A blast from the past? My mother-in-law cleaned out a
closet and found a box full of old LPs. Kid stuff. Lots of Disney LPs and
other stuff from the 60's. So here are my kids, unfazed, playing 45s and 33s
on a table from 1964, through a tube-only playback chain. Not a transistor or
opamp anywhere in sight (except that which turns on the LED). Chim chim
cheree...
August 17, 2005
---------------
The VCXOs finally came in! But still waiting for the special opamps I use in
the PLL loop filter (low noise RR singles). Then the first production HAGDAC
will be complete. Probably tomorrow. Have to check final loop tuning. So
many parts, now I have to wait for chassis pieces. Even so, I should be able
to start shipping HAGDACs and CHIME (the half-kit) by the end of the month.
Only thing holding me up now are the manuals. And aren't they a pain to write.
Right now, emergency layout for consulting project. That sort of chews up this
week for manual writing. Most often, clients need stuff done NOW! They talk
about it for two months, then demand a 1 month turnaround time. Sheesh.
I've decided to revive HAGUSB. Feedback from the community shows me there is
a market for such a stand-alone board. Will make it with headphone output and
sized to fit into a small plastic box.
Just let the baby mongoose go. Kids were so sad. She was finally ready to get
back to the wild. Well fed and rested. We found a spot where dozens of
mongooses live, where we'll be able to stop by once in awhile. Nice and safe
from dogs, cats, or other possible predators. Hopefully she forgets the human
contact soon enough.
August 16, 2005
---------------
Wondering if maybe I shouldn't have canceled the HagUSB. Posted the schematic
for DIYers online. Next thing you know, people are asking to buy any spare
circuit boards I might have leftover. Maybe there is life in this afterall. I
figured everyone would just buy one of those $29 converters at Circuit City or
Best Buy.
Baby mongoose doing well. So tame. Runs around the yard following your feet.
Perhaps the zoo could use it. What does one do with a pet mongoose? We have
no snakes here.
August 15, 2005
---------------
More parts in. Built up a 27MHz HagClock. Ran just fine! Heck, guess I'll
make this a new option. All the "universal" players probably use this
reference frequency (SACD, DVD, etc.).
Did me a long 3.5 hour bike ride yesterday. From here to Chinaman's Hat. Nice
and scenic, but very small shoulder most of the way. Nothing like having
mirrors whiz my your elbow. Legs held on, but the rest of my body was aching.
My ass hurt like hell by the end. Something tells me not to do this six hour
race. Not enough time to get in shape for it. Best to just focus on the swim.
Too many other things to do right now.
August 12, 2005
---------------
Argh. Bought the wrong opamps for the PLL circuit in HAGDAC. Forgot I changed
to a single type. So far, the new input circuit looks great, jitter on the
CS8415A is down. Signals everywhere super clean.
Then the VCXO factory said they san't make delivery this week. They're a bit
behind. Like ten weeks. Sheesh. We tracked down another supplier (Fox) that
has a few in stock and can deliver rest in four weeks. That would cover me.
Still looking into a TentLabs VCXO as an alternate. Guido seems to be a pretty
decent fellow. He offered to test a HagClock for me no charge. Can't refuse
that.
August 11, 2005
---------------
Nothing but consulting today. Looks like I'm getting roped into another
startup venture to capitalize on one of my inventions (new type of mass
spectrograph). Was just a consulting gig for many years, now turning the
corner with a lot of interest from investors. This won't have any impact on
Hagtech audio, as it will continue as long as I can still move.
August 10, 2005
---------------
Orders rolling in at a good pace this month. July was quiet. Either folks
were on vacation or my video was a hit...
Finally caught up from my own vacation. Back on schedule, things humming
along. Production CHIME board looks great. Parts coming, no backorders. Also
getting back to training. Next up, 3-day ironman. That is, do the swim, bike,
and run in separate races. One month until the Waikiki Roughwater swim, 2.4
miles open ocean. A week later, 112 mile bike around Oahu. And finally the
Honolulu marathon. All of these are the original inspiration and course for
the ironman (from the 70's). Ever wondered how they cam up with these
distances? Now you know the rest of the story.
Kitten milk. That's what the baby mongoose wanted. No wonder it was screaming
all the time. Now it's eating good.
Baby mongoose pet movie
August 9, 2005
--------------
Here's one you can relate to. I buy all parts for protos and production on a
credit card. Got one with a reasonably low rate, then I kept transferring
balances off of it when they got high to one of those 0% deals. Well now I've
done it. Had a late payment or two and now the APR is up to like 19%. And I
find nobody wants to give me any more of the 0% deals because I've done it so
many times before. Shucks. You should read the restrictions they put on these
new offers! Even if you make a late payment to another company they ding you.
Have you bought so much stuff online that your credit card number is ingrained
to memory? Mine was about 5 years ago. Oh well, now I have a new company card
to start over.
Trying desperately hard to get my financial house in order. Juggling four or
five credit cards and one bank line of credit. Balance transfers, whatever I
can do. Been trying to deplete some of the massive part inventory I carry.
Spent way too much on Clarinet chassis and transformers. Learn as you go. It
is a difficult balance between JIT and volume discounts. Always try to have
everything in stock because I hate to make a customer wait. My goal is to get
an item in the mail within 24 hours. So far, I'm achieving about a 95% success
rate.
Just bought a sheetload of parts to build first run of HAGDACs and CHIME. Good
thing I got that new card! Found myself short a few critical items to get this
first production unit up and running (already sold).
August 8, 2005
--------------
Started building up production HAGDAC and CHIME today. Finding myself short of
parts. Try and re-use what I can from previous protos, but that's not always
possible, especially with the surface mount stuff. Spent most of the day
filling orders (thanks!).
Yesterday I heard a funny noise outside the garage. What the heck? - it was a
baby mongoose (we mistakenly imported them here to eradicate something, but the
agency in charge failed to notice that one species was nocturnal, the other
not). Showed it to the kids. Tried to send it back into bushes or somewhere
safe, but it kept screaming and coming out into the open. Would have been a
goner. It kept following us around. So we put it up in a birdcage for the
night. Today "Squeaky" acts like part of the family. Eating and drinking out
of our hands. I'm suprised it lasted this long, yet it seems to be fine. No
interest in running away. Follows the kids around the yard. Wonder how long
before little riki tiki tavi takes a bite out of someone.
August 6, 2005
--------------
Back from vaca, 573 emails! Yikes. Loads of fun, kids had a great time. I
posted a few of my Yellowstone photos online.
Yellowstone photos
Also tried to make this 180 degreee panorama view off the top of Jackson Hole
ski area tram.
Teton panorama
One shot I did not include in the slide show...
Bisons
Trying to catch up on emails, orders, forum, etc. CHIME productions boards
arrived. Can't believe the UPS guy just left them outside the front door. As
soon as chassis and VCXO come in, I can start shipping units! Meanwhile, will
write assembly manuals. The long vacation has left me refreshed and ready to
push forward.
Going to try a TentLabs VCXO in the HAGDAC.
July 25, 2005
-------------
Off on vacation tomorrow! Can't wait to start photographing the beautiful
scenery at Yellowstone (before Disneyland). Long time since I've been to any
national parks.
Ordered CHIME production boards. Finally. Oh wow, the production HAGDACs just
came in. Lots of work ahead.
Just got notice that the UFO will show up in Fremer's column!
July 23, 2005
-------------
The work week never ends. Spent all morning tranferring the order form to a
new secure SSL server. Nasty Perl programming changes and a lotta of links to
be redone. But it runs! Changed banner color to purple to coincide with site
changes and an adjustment of pricing. You will notice that price increases now
end in "9" instead of "5". A few more bucks to try and recoup development
costs. No, I'm not trying to stick it to you. Doing my best to keep prices
fair and reasonable. Meanwhile, we're getting a huge tax increase here in
Hawaii (third highest in the nation wasn't good enough for us).
July 22, 2005
-------------
Production HAGDACs are done, on their way to me. Need to test them out with
final CHIME that arrived yesterday. Then I can order production CHIME boards.
The VCXOs should be here mid-August, chassis too, so we're all on schedule. A
little stressful trying to insure perfection with only a few days to go before
our family vacation. Have to get all circuit and layout issues debugged before
that big order is placed. Lots of risks involved in running a company.
Especially when it is all financed out of your own wallet! Much easier to
spend other people's money (good to be a politician).
Built up CHIME, tweaked, tested. Measured bandwidth of tube section to be flat
out to 155kHz (-3dB). See the 10kHz square wave below.
CHIME analog 10kHz amplification
Distortion at full output measured in at 0.03%, mainly second order. A very
clean tube amplifier stage! It was borrowed from the Cornet minus the EQ.
Gain turned out to be a perfect 30dB or so that I needed to make up for the low
HAGDAC output.
CHIME 1kHz distortion
Also tracked down a tiny bit of residual hum in the right channel. Odd, but
related to heater circuit. There was also a trace of crosstalk on the S/PDIF
inputs. I can fix that in layout too. Just need to verify operation of LED
circuits and I can go for production boards.
And where does a family in Hawaii go on vacation? To Disneyland, of course.
July 21, 2005
-------------
Got it working. Took me practically all day to get through the new DSL
installation and home networking (including wireless) issues. Finally back
online. New website up and running too. Halfway. Ok, it's the same pages,
just sitting on some other server. Will try to update links over the next few
days. Right now, many point to the old vacutrace.com site, which will die
soon. Uploading docs. Found this old movie of me skiing Alta three years ago.
Skiing
Great having lots of disk space online. Unfortunately, there will be a LOT of
broken links on audiocircle and audioasylum and my blog.
Meanwhile, building up the proto DACPRO. Everything fit nicely, the USB
section works great. Needs production HAGDAC card (not rev B as shown) to
test.
DACPRO proto
July 19, 2005
-------------
Had a cool thought, will use one of those "navigation" buttons for the
FLUGELHORN remote control. One button goes up/down, forward/back, and
left/right. I think I can make that do it all, and still make sense. Nice to
add new innovations for next generation of products.
July 18, 2005
-------------
Took 5th place in the Tinman triathlon yesterday, a mere 59 seconds from 3rd
place and the podium. Age group, that is. Once again a poor bike leg lost too
much time. Gotta get me one more mph! Shux, so close. And I reeled so many
in on the run. Frustrating, as I could have kicked in another gear on the run
(and felt some real pain). Final time, 2:15:24.
Spending big bucks today. Placed order for production HAGDACs and the CHIME
chassis pieces. Also need to build a production CONDITIONER so I can assemble
a full RACK (other than my own). Wrote a G-code program for my CNC to cut the
outlet holes on the back panel. Sure is nice to have accurate milling around
when you need it. Cuts great slots, holes. Even engraves.
So production schedule looking good. We'll be shipping CHIMES and RACKS by the
end of August. Once we start getting revenue from that, we can go ahead with
the DACPRO opamp version.
Tomorrow or Wednesday will be the big switchover for ISP and DSL. Website will
be down for several hours.
July 15, 2005
-------------
The HagClocks are here! Shipping all backorders today. Thanks for waiting.
Put finishing touches into HAGDAC. Finally can order production pieces, boards
for both HAGDAC & CHIME, and chassis with silkscreening. I pretty darn happy
with the way this project came out. Sounds terrific and the boards are pieces
of art. The HAGDAC is a great "engine" upon which to build a dac. Eventually
I will sell the DACPRO box too. Maybe get other companies to OEM the HAGDAC
for use in their own machine? Yeah, it's only 44.1k, but it is tweaked out to
the max. No gimmicks, no BS. Just real solid engineering using the latest
proven techniques. And a few new tricks up my sleeve.
July 14, 2005
-------------
Got the old MOTORPOD controller back from Thom (mackris vinyl playback). We're
collaborating on a quiet regulator with batteries circuit for his turntable
motor. Not only are we improving the regulation and noise, but adding the
capability to wind up that table to 78rpm. Still working on first proto.
Relayed out CHIME, hopefully for the last time. Put USB circuit down onto it,
added last few tweaks, changed LED circuits. Tracked down all of the remaining
glitches and fixed them. Racing to hit production on time. Need to order
chassis panels. Now to attack last changes and optimizations for HAGDAC.
July 13, 2005
-------------
Ok, I initiated a huge transfer of website stuff. Switching DSL providers,
changing web registrar, DNS, new host. Cancelling old ISP. Gosh, I hope this
all comes together without too much interruption of service. I even get a free
web cam out of it. Hate to lose email service or drop website for a time. Stay
tuned, the next two weeks could either be completely transparent, or a mess. In
which case you can't read this anyway.
Spending way too much time on this FRYBABY circuit. Thought I had it nailed,
but too much impedance loading by the iRIAA network is screwing up the signal.
And the output for MM has too much low frequency information showing up as a
parabola on top of the normal bow-tie signal. Ok, so 90% of the circuit is
great. My strive for perfection drives me to fix the loading and output stage
issues. Put it on hold for now. Gotta get the dac stuff done first.
July 12, 2005
-------------
Once I get this CHIME for sale, maybe I will start offering the CONDITIONER too
as part of "The RACK".
The RACK
Not sure if I'll ever have any takers, but will offer the RACK complete with
CORNET2, CHIME, CLARINET, 2 x CYMBALS, and CONDITIONER, with maple boards.
Similar to photo above. Pricing maybe $5995. That's a complete system minus
front-end turntable, CD transport, or interconnects. All tube electronics.
Not a great discount over the $6.8k retail, but then again, my prices are
already hugely discounted. It's like throwing in the rack and a CORNET2 for
free.
Yippee! FRYBABY boards just arrived. Can't wait to go build one up. Done.
Runs great. Will ship out for testing tomorrow (OEM only).
FRYBABY circuit board
My broadband hookup and ISP are reaming me. They delivery great product, but
the pricing is ridiculous. I get 10MB for a website! How can these guys stay
in business against the national firms offering 200x that? So it is time to
upgrade. Painful. Need to switch data pipes for the DSL (can't use cable
modem unless I use a pair of wireless routers), then maybe 1and1.com for site
hosting. They got a deal. I can finally start putting up larger pics and not
worry about email undeliverables. My site will probably be down for a few days
so I'll time it right as I go on vacation end of this month.
Just got notice, HagClock boards shipped today. I should be able to fill
orders by the end of the week.
July 11, 2005
-------------
Hmmm, guess a few folks are reading this. Ok, I'll keep it up for awhile. At
least until I finish the CHIME/HAGDAC project. Speaking of which, I just had
to add to the workload. So I made a DACPRO. Was planning on getting to this
eventually anyway. It is an OBOE lookalike motherboard for the HAGDAC. What
you get is the solid-state version of a CHIME. Small box, USB input, phase
switching, everything. Same HAGDAC, no tubes. Besides, I realized I needed a
platform for testing cards other than a CHIME (too cumbersome and you have to
watch your fingers).
DAC Pro
Hit a homerun! Did community listening tests at Stu's the other night. Sound
from CHIME was awesome. He swapped in some reference NOS tubes for easier
comparison. To me, it bettered everything we threw at it. Best sounding DAC
in the shop. Nods up all around. I can't wait to get it into production.
Meanwhile, finally getting around to landscaping the yard. I got fine dirt
particles blowing all over the place. Everything in the lab is covered with
it. What a pain.
July 8, 2005
------------
I made my commercial today. Like filming a movie. Did it in one take. Enjoy!
Hagtech Commercial
July 7, 2005
------------
I'm getting tired of this.
July 6, 2005
------------
Discovered a number of sources of CS841x jitter. Seems to be rather sensitive
to PLL filter components. Got it pretty quiet. Also, my digital output trick
helps quite a bit keeping transient edges out of the ground plane and analog
sections. Made a huge number of changes to HAGDAC and CHIME circuitry to
implement improvements. Can't believe how much is new. Adding a novel
differential input circuit to isolate 75 ohm termination and the RX chip.
Performs filtering, offset, gain, and balanced conversion for improved
switching and decoupling. Added an improved lock detection and looped it back
to the mute input, so with non-44.1k sources the output is automatically dark.
Dug out a little hum in the CHIME, was loose chassis piece. Now machine is
very quiet and clean. Spent a little time listening with headphones. Threw in
a temporary switch to check out the steep/slow rolloff feature of the DF1704.
Still looks like crap on a scope. Something totally asynchronous about the
slow mode. Steep looks perfect. Couldn't hear any differences though. Will
bring CHIME to our audio club meeting this weekend for tests. See how it
compares against other machines, compatibility, etc.
July 5, 2005
------------
Hope everyone had a nice holiday. Good to have a break and work on house,
yard, whatever. Brain functions so much better after a getaway. And so I am
back chasing the jitter in the CS841x circuit. Really suprised it is so
visible on the scope. Added a reference clock output to my CD player (that's
five holes I've drilled into it now) for convenience. The VCXO is rock solid,
but the input S/PDIF receiver is having trouble. I need to build up a partial
board and isolate the problem. Just in case, I designed a new front-end to put
in front of the CS841x, provides improved termination and isolation, cleans up
edges and has balanced outputs. This should effectively double the slew rate.
Here's a great new quote from Lance Armstrong: "pain is temporary, quitting
lasts forever". I'll try to remember that during my next race. While we're
at it, I've recently come across a few other gems. From a Philips ad: "talent
is not a commodity". Which gives us a new defense against outsourcing? And
finally: "consensus is nothing more than lack of leadership". Try and use that
one at work.
July 1, 2005
------------
I'm in the wrong business - saw an ad today for a $400 audio cable for the
iPod. What?! A couple of RCA jacks and wire that cost more than the iPod
itself? What is the point of a high quality cable when the source is MP3
(AAC) crap? This makes no sense. Anybody who buys this is a friggin dolt.
Did some more experimentation with that lousy S/PDIF transformer I pulled out
of my CD player. The narrow bandpass, especially the horrible low frequency
performance induces a ton of jitter. And this is before the receiver, just raw
interface signal. Top trace shows what happens with junk parts. Bottom is
same signal through a decent tranny. Both are cleaned up a little with the
addition of a peaked receive filter.
S/PDIF transformer comparison
This revelation caught me with my pants down. I can't believe a decent CD
player gets shipped with such a shitty part. Never expected this in high-end
audio. So now I have to re-think the CHIME front end. Maybe need a better
receiver circuit that can accommodate such waveforms. I'd like to remove as
much jitter as possible before it gets to the HAGDAC card. For DIYers its ok,
as they can just swap out the bad tranny. Nice long weekend to mull this over.
June 30, 2005
-------------
Wrote web page for HAGDAC. Available only assembled, because of the extremely
small surface mount parts. Yet it is still a bargain at $495, as it can be
used as the core of your own DIY converter box, or to upgrade an existing
player. Should be available in August.
HAGDAC web page
Fired that HAGDAC up today. No smoke. Runs way cooler now without the ECL. I
did a quick check on the two clocks to see if they locked. Well, they did, but
there was a ton of jitter! Oh my. So I opened up the CD player and used the
HAGCLOCK as a trigger reference. Then I saw what was really going on. Top
trace is from reference clock, middle is recovered clock from CS8415, bottom is
de-jittered recovered clock from my PLL.
Jitter
Finally tracked the problem down to a really shitty S/PDIF transformer in the
cd25 player. I can see it on the scope. Terrible low frequency performance
shifts the threshold levels all over the place, data dependent. The output
waveform was horrible. So I replaced the stock tranny with the one I use in
CHIME (DigiKey #470-1007), and viola, absolutely perfect waveforms. Jitter all
gone. This makes me really worried. Turns out the real S/PDIF jitter problem
is likely caused by crappy transformers. You can swap out $500 cables all day
and it won't fix a thing. The good news is, my reclocking circuit took a LOT
of the jitter out.
So how did it sound? I got the CHIME and HAGDAC all buttoned up and brought
them inside. Wow, even the cd25 sounded better. The soundtage was much deeper
and voices and instruments floated in space. I'm going to assume this was due
to the HAGCLOCK installation. Still, there is a little bit of harshness and
edge. I think this is what people mean by "etched". The CHIME, on the other
hand, had the same glorious soundstage and speaker disappearing act, but
without the etch. Smoother and more non-fatiguing. I could listen to this all
day without getting tired. Needs more testing. I have to check out left/right
operation. Phase switch works. Have to do some headphone checks, since my
"bass" is a touch on the soft side (CYMBAL amps driving the Vandersteens, no
rear corners in the room).
June 29, 2005
-------------
My cat finally came home. She ran away when the puppies arrived a few weeks
ago. Lost a bit of weight. I'd seen her roaming the mountainside. She
wanted to be petted something fierce.
Finished up the FRYBABY layout. This little machine is coming out really nice.
I like the concept, very clever way to do tonearm leads. Will be OEM only.
You may have noticed some of the picture links I have here get wiped out over
time. For example, just completed the HAGDAC proto version #2. When I post
the picture below, it's the same filename as version #1. So old one is written
over. Too much work keeping track otherwise.
HAGDAC test board #2
June 28, 2005
-------------
Wrote a temporary webpage for CHIME. I will be selling the HAGDAC separately
at $495 for those that just want the converter. Hammering a straight line
towards production. Should get remaining parts in to finish soldering HAGDAC.
CHIME web page
You can tell summer vacations are here. Orders way down. Happens this time
every year. Meanwhile, doing re-layout for FRYBABY. Working very hard to
strip cost out of this one.
June 27, 2005
-------------
Figured out some computer movie-making technology. My digital camera makes
nice .mov files, but needed to convert them to .wmv format for editing on PC.
Bought the coverter from www.movavi.com; works just fine, and I can cut way
down on file size by eliminating resolution (sound familiar?). Not that I
want to. Anyway, figured out how to put together scenes for this commercial.
Now to find time for shooting...
Boy, I sure can get sidetracked here. Spent the morning researching remote
control ICs. Finally found a practical solution. This is for the FLUGELHORN,
where I plan to build my own remote control. Probably five buttons, wood case,
metal top. Small, two AAA's, lots of oomph. Looking far into future.
Ordered production HAGCLOCK boards today. They usually take 3 weeks or so, I
never pay for the quick turnaround. Posted manual online, will update website
with links, and add line to order form. Can start taking orders tonight. The
board I sent out for test measured insanely good. Other board working in my CD
player. Confident this will be a hit product. With some modification, you can
turn it into a VCXO, or use as low noise regulator board. I think I'll try
that with a BUGLE. Make for a nice article.
Hmmm. Speaking of projects on hold, I find piles of folders of half-completed
designs. PICCOLO jfet headamp, SIXPACK surround preamp, FRYBABY, HUSH, POD
(the motor controller for Galibier), and CLARION 2a3 set. New ones started
include the turntable power supply / speed controller, and the FLUGELHORN.
June 24, 2005
-------------
Agonizing having to cancel a project. As a business, you have to focus and go
on a straight line towards ROI. No time or money to waste (this ain't
government). Realistically, the market for a separate HAGUSB would be pretty
small, as the price would not be justifiable. It's actually good to cancel
projects. And as early as possible. I've done this a number of times. My six
channel surround preamp is on hold, so is the HUSH. You have to look at what
is the best investment at the time. Nothing like financing development out of
your own wallet to keep the mind focused on results. So I spent the time to
integrate the USB circuit onto the CHIME motherboard. Fits pretty nice,
actually. I think this will be a better solution with more value to the
customer.
Meanwhile, finished writing manual for HAGCLOCK. Decided I couldn't wait, had
to install one into my MMF CD-25. Wow! Plenty of room inside this chassis.
Very easy to work on. Even the opamps are in sockets so you can replace them.
Found the audio crystal, a 16.9344M (not the microprocessor one of 12M)
connected to a SAA7327. Downloaded datasheet, pin 16 xtal input. Removed the
crystal and loading capacitors. Ran out of my own crystals, so just used this
one. Tuned it in for exact frequency. Mounted HagClock and wired up as
specified in manual (found some convenient +/-15V taps). Was able to keep
output wires nice and short. Viola! Ran perfect first time.
HagClock in use
Started soldering parts to HAGDAC. Argh! Just realized I left off the lock
detection circuit for the PLL. Sheesh. Will have to breadboard it, hope
for the best, because I ain't doing any more protos at $600 a pop.
June 23, 2005
-------------
Got the CHIME board in. Populated and ready to fire up. Not much it can do
until I build the accompanying HAGDAC in a few days. Although, it does show
that my mechanical mount for the HAGUSB card isn't going to work. Ok, it works
but I don't like it. Not good enough for customers, kinda kludgy. So I had to
rethink this whole USB strategy. Looking at asylum and net, there seems to be
plenty of low cost USB->SPDIF converters. Mine isn't going to be any better,
using the same parts. No value added. So change of plan here (once again
going in circles), going to put HAGUSB circuit right onto the CHIME board.
Will get around the surface mount problem by selling boards with the USB chip
already mounted. Circuit is still optional, only populate the other parts if
you want the functionality. Glad I tried this out before buying production
pieces. Unfortunately, I will have to do one more round of CHIME proto, but I
don't think it will impact schedule any, just have to prove out the addition
of USB.
Meanwhile, project FLUGELHORN has been resurrected. Still working out
specifications and architecture. Yeah, I know, there are too many projects
going on at once. It's a TRUMPET phono with matching linestage all in one box.
Not a half-kit, assembled only. Will be all-out assault for class A honors.
New chassis style, XLRs, remote control.
June 22, 2005
-------------
I guess nobody liked my tweaks asylum post on aspirin as a resonant control
device.
Just desoldered all of the valuable parts from the original CHIME motherboard.
Ugh, have you ever done that? Sure takes some work to get out the multi-leaded
parts such as the transformer, selector switch, and volume pot.
Been noticing how hard it is to debug machines (especially DIY) at customer
sites. That is, via email. The one MONOGRAM I built recently came back for
repair. Turned out to be ok, was a short in the phono cable. Now why didn't I
suggest that before it was sent back? Another one is an OBOE we've been
chasing hum for a week. Back and forth every day. Customer did discover a
Zobel network was needed on the headphone output to tame the opamp as it drove
his reactive 64 ohm loads. Fortunately, there's a nice spot on the board to
put it. We've tried almost everything, now thinking it could be dc or other
really bad noise on the power line. Will keep you posted.
When I don't have a lot to say, it's usually because I spent a lot of time on
consulting work, which I don't want to bore you with.
June 21, 2005
-------------
Tried HAGCLK at 33M to see if it wanted to go that fast. Didn't startup, at
least not with the standard values. The 11M and 16M work great. Discovered it
doesn't need amplitude adjustment for JFET bias. So I can simplify a little
for production. Frequency adjustment not necessary either for DIY.
Then, powering up the CNC to cut CHIME panels, the lab PC died. Sheesh, that's
the second one in a year. Gotta steal the kids game machine, hope they're not
too pissed. Just need a DOS machine, maybe I can find something on the side of
the road. Ok, got the pieces cut. They really don't look too bad, using the
laser printed decals and clear lacquer (same as CLARINET kit). I think the
trick is to really use a light spray so the paper does not discolor.
Meanwhile, a sideways venture with a major dealer for an "accessory" is back in
motion. I hope it can take off, as it opens up a new revenue stream and
possible storefront for another piece of gear I have in mind.
June 20, 2005
-------------
Forgot to add a 3V output option for HAGCLK. This turned out to be pretty easy
to do. Product does not need to wait for CHIME, so I can start writing the
manual. Sent one off to get tested for jitter. Got a temporary web page going
(no, not on sale yet!). Added some new measurements.
HAGCLK web page
Mostly consulting work today.
June 17, 2005
-------------
Got HAGCLK boards in. Best part of this job is stuffing components and
soldering them in place. I just love building a new board for the first time.
Ok, so I'm a geek. But the feeling of assembling a new piece of art (that's
what it is to me) and getting it right is rewarding. Nailed the HAGCLK on the
first try (instead of the normal three). Probably because I spent so much
effort on hand-built prototypes. Regulators fire up quickly and quietly,
excellent transient response, oscillator tunes right in. I can adjust
frequency to single-digit ppm and tune amplitude for a perfect sinewave. Now
if I could only test the darn thing for jitter performance.
HAGCLK
Ordered the new CHIME board. I need to make sure I got all the mechanics right
before I spend any production money on chassis parts. Plan to build up a full
CHIME with new daughter cards. Then listening tests and final tweaks. After
that, I can put the HAGCLK in my CD transport to see what difference that makes
(hopefully none, as the HAGDAC reclocking fixes jitter problems anyway).
June 16, 2005
-------------
Got new HAGUSB boards in. This time powered up perfectly, ready for
production. Did BOMs today for all of the new boards to try and figure out
final pricing. I think the HAGUSB will come out at $85, assembled only
(because of the surface mount parts). It's a perfect little board to plug into
a CHIME, or retrofit into your existing DAC. No power required.
HAGUSB
The HAGCLK is a bit more expensive at $35 half-kit, $125 assembled. HAGDAC
came out less than I expected and will sell assembled for probably $495?
Depends on how long it takes to assemble and test. The CHIME will be $95 half-
kit and $1895 assembled (includes the HAGDAC and HAGUSB). That's higher than I
was aiming for, but no way to make it any cheaper without cutting performance.
Consider the CHIME will compete with $10k and $20k DACs, for a little
perspective. Or compare with another fine DAC, the Benchmark; a nice machine
that upsamples to 24 bits, re-clocks for jitter reduction, and has a volume
control. Add passive I-V conversion (instead of the opamp feedback circuit),
super regulation, passive LC Bessel filtering, and a phase switch. Now what
would you pay? Add an input selector switch, USB capability and the ability
to select between fast or slow digital filter rolloff modes. Now what would
you pay? Add a full-blown vacuum tube output stage with constant current
sinks and tube rectification. Now what would you pay? Ok, I've convinced
myself. Any way you cut it, the CHIME at $1895 is a bargain. The half-kit
will cost you DIYers about $1005 in parts.
June 15, 2005
-------------
Gads, $600 more clams to buy new HAGDAC boards. Design came out really nice,
sure hope this cuts it. Also did relayout for CHIME, so it is ready to go too.
But I think I'll wait on it. Can test new HAGDAC on my existing CHIME proto.
Changes were pretty minor, just the LED circuits that indicate receiver and PLL
locking to input signal. I didn't like the LEDs on front panel, so I moved
them to the top. Tried to put one LED in center (same position as first tube
in Cornet2), only to realize the HAGDAC itself was in the way. So split into
a pair of symmetric LEDs. These, of course, are optional for half-kit
builders. I had also originally intended to put a 1-0-1 mA analog meter on
front panel to show action of PLL. I like the concept, but couldn't locate
any meters that weren't totally cheap in appearance.
I feel like I'm juggling too many balls in the air. That's four circuit boards
at the same time, and they all interconnect or interact. Must all fit and work
together. Any time I changed something, there would be a ripple effect, which
caused a change in something else. I look forward to finally getting it all to
market. This has been quite a big undertaking. Oh gee, just realized I have
to get production chassis parts on order. Long lead time.
June 14, 2005
-------------
Added new PLL onto the HAGDAC layout. It fit sparsely so I had room to play
with. Ended up ripping almost everything apart on left side. Re-optimizing
component locations for better trace routing and less crosstalk. A few minor
circuit mods and placement is complete. As in most cases, it takes three
layouts to get it right. First one almost always has some major issue, second
one is very close, third gets it right for production. The Bugle took two,
Trumpet and VacuTrace four. It costs more, but I really like to get it right.
June 13, 2005
-------------
My wife suggested that a "bAd" contain movies - those short little funny clips
that people pass around on the net. I couldn't agree more. What's the point
if they are not entertaining? So maybe I will try that. Have an idea already
for movie #1.
Saw this great quote "Simplicity is knowing when less is too little and more
is too much" (Philips, Business2.0).
Got the HAGDAC layout started, fixed a number of decal issues. Ripped out old
stuff, will add new PLL tomorrow. Ordered a ton of parts. For building up all
of these new proto boards I have coming in. Sheesh, it's like I put in part
orders from DigiKey or Mouser at least once a week. That's a lot of NRE.
June 12, 2005
-------------
Snagged a few pics from the race. Scenery was wonderful. Just too hot.
Honu half-ironman, Honu finish, Honu after
All these dirty new (old) LP records. What to do. Thinking about automatic
cleaning machine. Wish I had some large suction cups so I could cover the
labels, then spray with high velocity water gun to really dig the crud out from
the grooves. I don't think anything special is needed other than water and
perhaps a little dish soap for the really bad ones. Then a blow dry. I really
haven't done much in this area, but it seems to me that more than just a vacuum
machine is needed.
Here's an interesting stat: Hagtech has sold 657 phono stages to date. And an
astonishing 87% have been half-kits! Guess that makes one thing pretty clear.
Hi-Fi+ article by Foster was great reading. His discussion of the quality of
various pressings and VTA (two separate issues) is revealing. I too, have
heard stark differences between LPs of the same recording. Makes collecting of
rare or quality vinyl all the more interesting. Same thing with tubes, not all
12AX7s sound alike, as most of you know.
Had another whacked out idea today. I invented the "bAd". That's short for
WebAd; sort of like a WebLog, but instead of words, a collection of ad images.
Thinking outside the box here. You see, magazine ads are hideously expensive
for us little guys (although worth every dime if you can afford them). So are
intrusive banners and popup ads. So rather than push, how about pull? Ok,
maybe this is stupid, but seems to me a real inexpensive way to get ads out
there for public viewing. I'll try it out for awhile. See what happens.
WebAd
June 10, 2005
-------------
Dang, got there too late. All the mercs were gone. Got me a London and a
living stereo. Also a Harry James, Sinatra, Severinsen, and of course Herb
Alpert. Ran into Stu afterward and he hands me another London and an LSC-2323
(Kondrashin)! A few other interesting finds were just too trashed to bother
with. Those who got in early probably got a haul.
Gave away a free UFO with a Bugle Pro this morning. Yeah, the UFO is not
selling well. Way cool idea, no packaging. Wonder how long before someone
copies it. Anyway, giving them away free with all Bugle Pro's now.
Cranked out another board layout. This one a little power supply circuit to
drive an electron bombardment filament and to provide a bunch of bias voltages
for an ionizer. Just busy consulting work. Took care of a lot of tasks this
week. Leaves me open to the HAGDAC relayout first thing next week. Then all
these new boards trickle in for assembly & test.
June 9, 2005
------------
Oh my. We got two puppys today. The kids are thrilled; I can't get anything
done. Must hide in lab. Which is ok, because I actually had some machines in
for repair. A Trumpet died right after a customer brought it home. Sheesh.
Haven't quite gotten to the bottom of it, but looks like a broken power switch.
Didn't take the time to nail it down, just put in a new supply for now. It's
not like my warranty costs are a problem. There has only been one other true
Trumpet failure, and that was a blown transformer. One other had switch pushed
in (wasn't that handle supposed to protect it?), and then two with the original
manufacturing defect of too short spacers under the chokes. Not a bad record,
for three years of production.
The other machine was a Cornet someone built but never got fully debugged.
Turned out to be a 1nF was 10x too large. It looked just like the correct
cap in the other channel. Nice chassis work. Chock full of ultra boutique
parts.
Tomorrow is LP sale. Hope I can get out to see if I can snag some old Mercs
or Dogs. Thinking of perhaps some 78 monos. I want to see how well my Bugle
Pro plays on the TD124. Maybe there is a mono cart in my future? And that
gave me an idea in the shower. People have been asking about motor electronics
for TTs. Maybe I can get these tables up to 78rpm? Perhaps its not a motor
replacement, but better drive electronics. One that can tweak speed and run 45
or 78 without switching pulleys. Hmmm.
June 8, 2005
------------
Added up parts, $37 for HAGCLK. So for about $75 you can build a half-kit.
Also makes a nice low noise regulator board (cut it in half).
Did relayout for HAGUSB. Fixed stupid connector pinout mistake, changed form
factor to put mounting holes in middle; made it a little more rugged, holding
the USB connector and cable in place (isolated from chassis metal). Changed
ground pours for better isolation under transformer. Input and output grounds
completely independent, so PC noise does not infect DAC. Also added TTL output
for SPDIF just in case anyone could use it. Makes a nice standalone USB->SPDIF
converter, or put inside your existing DAC. Ordered test boards for both
HAGCLK and HAGUSB.
Finished up redesign of PLL for HAGDAC. This version uses super-low jitter
VCXO (ecliptek) and the phase detector in the 74HCT9046A. Add a low noise
OPA2342 opamp for the loop filter and the circuit ends up much simpler than
what I had before. The original ECL circuitry burned a lot of power, used many
parts, and had too wide a tuning range. We're talking a factor of 1000. Hope
to start the relayout (agonizing) tomorrow.
Meanwhile, an old consulting client called up and has another job. This is
good, as it should pay for the rest of the CHIME/HAGDAC development.
June 7, 2005
------------
Just ran into an excellent article on positive feedback online (they're doing a
review of some of my components) by Lynn Olson regarding output stages. It
speaks in plain language about the current loops involved in the various
topologies. Very clearly explains what is wrong with the common transistor
class AB amplifier. It also concludes that perhaps the best approach is exactly
what I did with the CYMBAL. This is no accident, as I had been Lynn's and
others work for years.
Lynn Olson's ETFP
The CYMBAL is actually a little different. I don't run a pure current source
on the output stage because of the hard clipping that can occur. I use a
resistive source that then causes the amplifier to fold into class B, producing
a softer and more benign clipping. I also moved the current source balancing
to the input stage, where it can better maintain symmetrical operation. And of
course, no feedback. The other change is the 6H30 tubes instead of DHT, which
keep hum levels far lower (0.02mV).
Had been thinking about putting a HAGCLK onto the CHIME motherboard. Might be
nice to have an optional reference clock built-in. But then, if not used,
is a source of interference. And there is also an issue of trying to deliver
and terminate a clock into the CD transport without causing ground loops. So
I decided against it. The preferred method is to put a HAGCLK intimately
within the CD chassis.
Did layout for HAGCLK today. Came out a little larger than I expected, 1.7 x
3.7 inches. The regulators take up half the board! Very clean, with ground
pours on both sides.
HAGCLK layout
June 6, 2005
------------
Nothing like an airplane ride to clear your mind. Solved a few nagging issues
in my head. Figured how to improve regulator performance and speed up turn-on
delay at the same time. Also made two outputs, one dc coupled, the other ac.
You pick which is needed. Added test points to regulators so board can be used
as a standalone low noise regulator for other applications.
Race went well. Placed 11th in age group (3rd from Hawaii!) out of 56. Swim
was very fast (lots of draft) with a good bike leg to set me up perfectly for
the run. However, 90F Kona heat, humidity, and sun hurt everyone on the run.
No mile markers so I didn't realize I had dropped pace. Still, 5:41 on a tough
course.
Organizing today. Figuring out what needs to be done next so we can get these
products to market. Updated schematics for HAGCLK, HAGUSB, HAGDAC, and CHIME
(they all go together). Will start relayouts tomorrow. Final proto builds
this month. Then final testing and tweaks for production. Order production
parts in July, write manuals, etc. I expect schedule to bring an August ship
date. That's for all four boards. Tentatively I plan to then do a new HUSH
(ultrasonic heating) design. Not sure if I will finish the CLARION.
June 3, 2005
------------
Can't get this HAGCLK regulator to start up fast. Too much filtering in both
the feedback and reference. I like my choice of reference, the LM385 because
it allows me to change architecture and drive it from the input, instead of
output. That solves startup problem. Need circuit to fire up quickly so that
oscillator output is present before CD player exists reset. Hmmm, maybe I'll
add an extra reset output just in case.
Gotta call it a day. Need to pack up my bike & gear for the big race this
weekend. Half-ironman.
June 2, 2005
------------
Added comparator to HAGCLK. Pretty clean output signals for a hand-built
proto! I added output matching to load a short section of twisted pair
transmission line (a few inches to connect board to CD player). Doesn't
matter how clean signal is on board, only where it ends up. Measuring with my
P6057 probe the waveform is very nice. Rise and fall times under 5ns. No
glitches or anything funny (actually 2V/div).
HAGCLK proto with load
Board will have two adjustments, one for sinewave amplitude, the other for
frequency tweaking. Finished up schematic, ready for layout. Can be used for
11.2896, 16.9344, and possibly 33.8688 xtals.
Changing the SIP connectors on CHIME to lower HAGUSB closer to main board. Had
an interference with rear chassis panel. Can't find anything with a nice 0.25"
dimension. Stuck at 0.165 or 0.291. Must find #4 screw spacer.
June 1, 2005
------------
New counter came in. Gotta check it out and clean it up. Fastest eBay service
I ever had. Plugged in and it works! I fired up my oscillator and tuned for a
11.28960 reading. The Tek read 11.28918, and rose as it warmed up. In a few
minutes it was up to 11.28940 until it crapped out. The HP was steady. Hmmm,
was my custom JFET VCXO really that steady too? Maybe I should rip the OCXO
out of the Tek and wire it up as a reference. This also means my actual
frequencies were higher than I thought. My CD player output clocks at
11.29080 on the HP, which is +106ppm, out of redbook spec!
Yeah, the 10MHz OCXO reference in the Tek still puts out a great signal, only
the LED display fails. After a warmup, the HP reads it as 10.00001MHz. That
proves the HP is virtually dead on.
Built proto of HAGCLK. Found issue with sulzer regs, they don't turn on! The
reference gets power from regulated output (very clean). But what starts at
zero stays at zero. So added a tiny startup bleed from input supply voltage.
Will rethink how I want to do the regulators. A quick analysis of stability
looks pretty good, nice clean transient response and correction. These
discrete regulators are a pain, but I can see how they'll be much lower in
noise, especially in the lower frequencies. Voltage ramp-up is quite slow,
could be a problem with some CD players that expect a clock output without
such delay.
HAGCLK proto
Proto is a little ugly, trying to assemble fast. Output waveform is a nice,
low distortion sinewave right on frequency. I will add a variable capacitor
when they arrive for tuning to exact nominal. Will add comparator circuit
tomorrow. Now if I only had a jitter testing machine. Maybe I can try a long
piece of coax as a delay line?
May 31, 2005
------------
Drew up schematic for HAGCLK. Will build up a proto, plop into my CD player.
Also thinking about possible future products. What is it that sells? Well,
the half-kits do pretty good, but there's no profit involved. The Bugle
continues to sell well, the Oboe not. Why? I did the Oboe for the sole reason
that there seemed to be a sweet spot in the market for Bugle-like performance
at a bargain price. No, more to it than that. I guess the Bugle is a rare
beast that fills a hole in many systems. I think the HAGDAC, HAGUSB, HAGCLK,
and the CHIME will do well. Buy them all or one piece at a time.
So maybe there is another possible market, the full-on preamplifier. That is,
take everything I've done to date and morph into one big front-end. Use the
balanced circuits and power supply from the Trumpet, add the HAGDAC, HAGUSB, a
differential linestage, and remote control, put into one box. This would be a
phono/dac/linestage. Just add a table, transport, and amplifiers. I think,
however, the market wants a flashy box. Probably mix tubes, X7s and N7s.
Yet again buying more parts. This time some clock stuff, but mostly for
consulting project. Haven't heard back from my other possible client. What's
up with that?
May 27, 2005
------------
More parts on order. Sheesh, this development stuff adds up fast. Might bite
the bullet and order the highest grade (lowest jitter) VCXO next week. Keeps
the ball rolling. I can then concentrate on the circuit improvements and roll
them into a new HAGDAC layout. Expecting to have production machines in stock
ready for sale by August, probably the best realistic schedule I can do.
Meanwhile, whipping up a schematic and layout for a possible HAGCLK. No point
letting all this new knowledge go to waste. Will be a generic low noise
oscillator for use as a reference clock in CD players. Pick your own crystal
frequency. Designing in some low noise regulators (Sulzer style), so it is all
self-contained. Only 4 wires.
Rest of day spent consulting on a power supply card to drive filament for
electron bombardment ionization. Using new MAX1932 adjustable APD supply for
the bias.
May 26, 2005
------------
Busy with kids graduation (from pre-school & kindergarten!), but got some more
testing done on oscillators. If only I didn't have to pull frequency so far.
Red Book spec is +/-100ppm, which is pretty darn sloppy. I need to have that
well within my pull range (plus center tolerance) for a re-clocking PLL. Might
have to just bite bullet and pay the big bucks for professional VCXO. Still,
I've learned lots of good stuff playing with and tuning these circuits. Made
some relative improvements to the standard textbook schematics. Hey, maybe I
should make this a DIY kit - the standard 11.2896MHz low jitter oscillator.
Could be a very low cost half-kit ($25?), since board size is small.
So many projects. Never forgot about the HUSH (hagerman ultrasonic heating),
or maybe I should call it HAGFIL, just has trouble. The circuit was based on
the classis Royer converter used in lamp ballasts. Nice way to make a pure
sinewave converter and I thought clever solution. Only problem is that it
only operates on capacitive load. The resistiveness of a filament squelches
the tank circuit. Dang. Simple it was. So changing to a forward converter
to do same thing, only regulated. With some output filtering will produce
pseudo-sine. So after CHIME (and HAGDAC, HAGUSB, HAGCLK), I'll get back to
HUSH and CLARION 2A3/300B SET. Meanwhile, I continue to take requests and
customer feedback (on forum), such as the turntable motor speed control.
May 25, 2005
------------
Bought new counter on eBay today. Hopefully it works. Not bad when you get
7 digits of HP precision for $31. Only piece of new test equipment I've
bought was the USB digital scope (stingray) from Saelig to run with VacuTrace.
Great eBay deals on 70's and 80's vintage equipment. And I mean best of the
best. Of course, I've had a few duds, two counters gone bad, and one 7a13.
My fried counter seems to work for a few minutes after power on. I just can't
trust the numbers until it warms up, though. Wondering if it is reading high.
My CD player gets received at 11.29048MHz (that's +78ppm). My VCO pulling
about +/-50ppm. I was having trouble pulling crystal lower than nominal,
maybe it's just my meter? The Colpitts circuit pulls high easy, Pierce pulls
low. Worked hard today to get Pierce running as cleanly and as non-distorted
as the Colpitts. Worked out some neat improvements. Went through a dozen
proto circuits. Reusing parts I still ran out of JFETs. Need to buy more.
Came up with output buffer using P channel. All this work coming up with a
nice two-fet oscillator, and it still may not pull enough. Might have to
settle for the COTS version. No point doing such a clean low jitter circuit
if it doesn't lock to half the CD players out there. Check out the bunch of
proto circuits assembled over the last few days.
Proto oscillators
Guess I could always do layout with both circuits. Now I need to wait until
more parts and counter arrive.
May 24, 2005
------------
Got new VCO & PLL working. Locking to the VCXO samples I got. Can't see any
jitter, but my scope only goes to 1ns/div. Still, no fuzz. New Colpitts
VCO can be pulled higher in frequency, but not lower. Not sure what that's
all about, I would have assumed series mode would be a lower nominal. Can
pull about 3 kHz. Built a number of configurations, but can't get frequency
below the 11.2896MHz. Purchased version has 25ps jitter spec. I want to do
better. Try again tomorrow. Seems the circuit gain is dependent upon the
same capacitance I need to vary. Not enough loading and the oscillations
snuff out.
May 23, 2005
------------
Built JFET VCO today. Wow, much cleaner than BJT version. Must be the non-
linear loading on the XTAL? Very clean sinewave (test at 12MHz). Added output
buffer and stumbled upon a great inductor trick to do both constant current
bias on JFET and high pass filter and dc offset removal all at once. Hey,
that's what it is all about, adding value and innovation. Hagtech is not a
me-too type of company. We deliver improvements. This is yet another minor
example, buried deep within a circuit where nobody notices.
Found source for off-the-shelf VCXO. Only problem is the 12 week lead time.
Got samples. Will build up full PLL circuit for both VCXO and my discrete
version for testing.
Brought the CHIME to our local audio club meeting. They liked the polarity
switch. We didn't play it as the guy from FAL loudspeakers was in the house.
Fascinating demo (FAL)! Now I get it, Ed from the Horn Shoppe also told me to
try this - toe in the speakers so that they cross way in front of the listener.
The FAL were facing each other, essentially sideways. I could not believe the
soundstage effect this produced. The sweet spot was about ten feet wide. You
could sit on either side of the couch and the soundstage was still there.
Speakers totally dissappeared, and the treble rolloff was not bad at all. The
effect was cool. Ethereal soundstage, but not focused. Not my taste, as it
was bigger than life, but fascinating nonetheless.
May 20, 2005
------------
Wow, this is so cool. Got the HAGUSB hooked up to my laptop playing a CD out
to the CHIME. And it works! I wonder what else the USB connection can do.
Maybe play all the iTunes stuff? Noticed the volume control in windows media
player was functional. Not sure who was recalculating the bits, the laptop or
the digital filter in the PCM2704. Hopefully when set to 100%, the bits are
pure and not corrupted.
Other problem of the day is to find a transformer isolated 3V 3A supply running
off of 5V input.
May 19, 2005
------------
Nothing but consulting today. So I'll talk about the new frequency meter I
need to get. I buy almost everything I need on eBay. Tons of stuff available,
but lately a lot of crud. Buy the good stuff, look for what others are bidding
on. Spend a few more bucks and save yourself a headache. My lab is full of
Tek and HP stuff. For a counter, looking at old HP units with lots of digits.
Want to make sure I get credible measurements of the HAGDAC 11.2896 VCO.
Doh! Just had a Homer Simpson moment. Finally tracked down the problem with
HAGUSB, wrong pinout! Shoot, that is really lame and embarrassing. The
schematic in the PCM2704 data sheet is drawn wrong on page 27, right on the
next two pages. I just blindly assumed their USB pinout. Anyway, rewired the
board and it is now recognized. Will test some actual sound tomorrow.
May 18, 2005
------------
Audio club meeting this weekend, maybe I'll bring the DAC (non reclocked) in
for a listen. More proto parts on order. I'm curious to see how the JFET VCO
version works. Here's a shot of the proto I built yesterday.
Proto oscillator
It's a little beat up because of all the tweaks I tried, but is still a good
example of construction technique. I like to use the plated-through proto
boards. A little thought to the layout and simple circuits are pretty easy to
make. Even at 4MHz, this circuit ran very clean with no noise issues. The
secret is the bottom side. Use a nice thick ground connection and short leads.
No wires needed, just bend and solder the component leads. This board took me
about 20 minutes to make. For other examples, check out the work by Jim
Williams of Linear Technology.
Spent most of day on debugging consulting boards. A very nice stack of PC/104
cards. Bottom one is a purchased CPU (modified), others are custom hagtech.
The stack provides all the electronics necessary to drive and readout an
unusual experimental mass spectrometer. So far working great. The channel
electron multiplier (dynode) readout card has some issues. Each card has
feedthroughs so they can be stacked in any order. First generation was a mess
of cables.
PC/104 stack
May 17, 2005
------------
Spent the day building oscillator circuits. Easy to get them to work, hard to
tune into really clean sinewaves. Got bipolar version working quite well at
4MHz (no 11.2896MHz xtals on hand). Can't find my stash of JFETs, will order
some tonight. Plan to build several more working discrete VCOs before I decide
on final approach. Definately a few bugs in the basic Colpitts circuit that
most people use, trying to tweak and modify for improved operation. Suppose I
then have to fork over more cash to buy some test boards that can be kludged
onto the existing HAGDAC card (which cost me $650 for a few protos!). Product
development is not cheap. I probably average one or two deliveries a week from
Mouser and DigiKey. Hey, it's great fun, don't get me wrong. Just need to
keep in mind that long-term profit should be a positive number, not negative.
May 16, 2005
------------
Great weekend training. Lotta miles. That climb up to Hawi not so bad (until
you hit the wind). Live Hawaiian music with hula after dark. The sound of the
ipu (or any drum for that matter) is difficult to recreate properly in your
living room. The combination of transient attack followed by a muted decay
requires both dynamics and textural capability. You can hear each slap is
individual, in timing, location, and intensity. It's like fingerprints.
Meanwhile the voices are floating above yet still connected. I wonder how this
would sound on CD, could you still hear the dancer's feet?
My problem today is finding a VCXO in stock. Perhaps I'll need to make my own.
Research leads me to a Colpitts type, think I like the JFET version better than
NPN. Operation is at series resonance so it can be pulled a bit using varactor.
Prefer to just buy one of these already optimized, but sometimes small orders
get shunned. Either way, it ends up being simpler than my ECL circuit.
Meanwhile, gotta get some more (consulting) boards built up.
May 13, 2005
------------
No work today, packing for weekend trip to big island (people always ask,
"where do you go on vacation?"). Crammed bike into box. Once again marveled
at the good use of carbon as a lightweight material with excellent damping
characteristics. Thinking it could make a nice audio chassis or turntable. I
wonder if anyone has used carbon for a platter. Or for tube dampers.
Discovered the 74HCT9046A improvement to the basic cmos phase detector. Clever
way to fix the dead zone issue. Different in that the VCO cannot be disabled
separately, but I think tying the cap pins to ground and running zero
programming current should do the trick. Don't want any unwanted asynchronous
oscillations in this circuit.
May 12, 2005
------------
Some days are just so hard to get anything done. Take kids to school, then 9am
I'm barbecuing chicken. Lunch date in town, stops for other errands. Meet
friends from Montanta for dinner at Buzz's. Never made it to the lab. But I
did get to sit down and play some more tracks through the CHIME. So nice. It
sounds pretty darn good as-is, without the reclocking. Investigated VCXOs and
other phase detector alternatives. Probably should have gone this route from
the beginning, just happened to really like my LC ECL VCO. At least that part
works fine. Anyway, designing alternate PLL. Gonna have a shootout.
May 11, 2005
------------
Trouble getting PLL to lock. Went back through calculations, a bit more
rigourous this time. Found small issue with the pulse transient suppression
capacitor value. Not sure I like this ECL phase detector. Particular about
input edge rates. Finally got it to lock up, but still some instability.
Tuned in some other signals, PLL still needs help. Then, as if on cue, my
frequency meter went on the fritz.
Tired of debugging, so I just bypassed PLL to try out system. Put HAGDAC into
the CHIME and went inside to see how it sounded. Easy to compare with raw CD
player since volume control can match levels. Was totally relieved to hear
nice open music. A bit of edge was taken off, smoother, with no loss of punch.
Bass seemed more powerful, that makes no sense to me. I can't see how that
would happen. Finally, I was able to listen to this one track, a Chinese
instrument that just glares, actually didn't drive me out of the room. So
we're mostly there, just need to clean up the PLL reclocker.
Took some new photos of 1kHz square wave and 20kHz sine. These are all the way
through the tube circuits.
HAGDAC measurements
Starting to get unhappy with my ECL PLL approach. Maybe it's just frustration.
Time go circle back. That's what I always do. Don't force it. If it's not
perfect, go back and change directions. Thinking I should go the VCXO route,
must ponder for awhile and mull the universe. Still convinced I need the
reclocking, so HAGDAC ain't gonna ship until excellence is achieved. You can't
imagine how much time I spent on the Trumpet.
May 10, 2005
------------
Was browsing through an old diyaudio thread, where everyone agreed that analog
filters do not have the pre-shoot or ripples prior to a step response, unlike
the digital filter implementations. Well folks, that ain't entirely true.
They're called transversal filters and go way back. Originally used for cable
equalization in communication systems, they also provide echo cancellation and
other complex filter realizations. Blumlein was into these. I've used them,
very effective. The most recognizable implementation is the sharpness control
on your old TV or VCR. That's an all analog transversal filter that adds both
preshoot and aftershoot to a step response, while also reducing the actual
risetime. Just wanted to clear that up.
CHIME motherboard now up and running. After accidentally soldering in the low
voltage transformer backwards, it came up with no issues. Not one resistor
value had to change (paper & pencil calculations were spot on). Amplification
looks great, clean signals with wide bandwidth, flat up to 170kHz. Lots of
gain, 33dB, but that is needed because I use a low resistor value for I-V
conversion. It is ready for a HAGDAC.
Got most of the PLL operational. Filter opamp was oscillating, wierd, maybe
because of the low ac gain (opamps worst condition is unity gain). VCO looks
good, but phase detector not locking. Loop response way slower than it should
be. Better double check calculations tomorrow.
Meanwhile, pics came in from last triathlon. A respectable race, but not too
fast. Some guy behind me tried to pass and forced a sprint to the line.
JAL triathlon
May 9, 2005
-----------
Dang, another bad HAGUSB, this time the 12MHz oscillator starts up. Everything
looks great on the bench. Plug it into XP and it's "device not recognized,
hardware not operating properly". Can't find much info on the PCM2704, but
seems it should be plug and play without any software.
Here's an interesting marketing tidbit - I got more orders on Mother's Day than
the entire two weeks prior. Usually this effect is more pronounced around
Valentine's Day.
Finished building the CHIME motherboard. Came out very nice and organized.
Will fire it up tomorrow to check out power supplies and tube circuits. Maybe
can put an actual HAGDAC in for some real music.
CHIME
The HAGDAC and HAGUSB cards plug onto the back side, same as tube sockets.
CHIME daughter cards
May 6, 2005
-----------
Yes, I have once proved the laws of physics correct again. This time
calculating the loop filter values for a PLL. The formulas do work; I like to
put them into MathCad so I can play with various parameters to check out
sensitivity, etc. I had the synthesizer working pretty well but found a slight
instability at low frequencies (non-linear varactor tuning). Was way too
aggressive with the loop response, too close to the sampling frequency. Slowed
the loop down, changed to a slower and better opamp, voila! Great feeling when
all of the ducks line up. Of course, all of this instruction pays off by
applicability to the HAGDAC PLL. Different chips, but same concept.
Interview for a new consulting opportunity went well today. Yeah, hard to make
ends meet by selling half-kits. Not getting rich the way you might think I am.
Without the consulting, I'd probably be making minimum wage. If only I could
sell more Trumpets! On the other hand, working on a wide range of projects
really keeps you on your toes. Things I learned from designing cell phones may
apply in some odd way to audio. I feel sorry for those designers who've done
nothing but audio amplifiers all their life. So limited. The wealth of
knowledge found in other fields can be so beneficial. For example, the
capacitors made for high current pulse circuits (power supply, TV) worked great
in audio. That's where the low dissipation factor, metalized, polypropylene
and similar types came from.
I suppose this would also be a good time to honor and thank the lunatic fringe
experimenters and hacks for their hard work. Really, many of the breakthoughs
we enjoy in audio came from folks trying the most outrageous things. New
capacitors, different wire types, green pens, constrained layer damping, cones,
constant current loading, reclocking, etc. are just a few examples. Might I
add that a half-kit is a great platform upon which to experiment?
May 5, 2005
-----------
Focus on consulting today (my second job). Nice to sit at Starbuck's and crank
out embedded C code on my laptop while sipping coffee. Recently discovered the
most useful data structure; bit codes. Makes life sooo much easier when
accessing cpu pins as either bytewide ports or as individual pins. Just union
two structs! Highly recommended. I have to admit, software is addictive in
that you get near instant feedback of satisfaction when something works. Not
so with hardware, where you may have to wait for new boards.
May 4, 2005
-----------
I don't know what's up with this HAGUSB. Can't get the oscillator to start on
the PCM2704 chip. All pins seems to be wired correctly, power is fine. Very
happy with the way the layout turned out, though. Nice clean power and ground
planes. That's the trick to low noise and clean operation. Supply decoupling
is super critical.
HAGUSB proto
Yesterday I mentioned proper probing of signals. So I made a quick example to
show what can happen. Using five different probes, I measured the same clock
signal coming out of the DF1704. From left, two cheap 60MHz probes, and then
the professional Tek P6131, P5100, and P6057. Note the last two are 100x and
feature low capacitive loading. Only 1pF for P6057 versus the normal 10pF or
more for typical 10x probes.
Probe comparison
Clearly you need to use the right tool for the job or you can be easily misled
about the truth.
May 3, 2005
-----------
Something odd with the slow rolloff mode with the DF1704 digital filter. The
output signals get all smeared in time with respect to asynchronous sampling
clock. Just not right. Normal filter mode produces superb looking waveforms.
Stunningly perfect 20kHz sinewave, very clean 1kHz bandlimited squarewave.
Analog filter does a great job getting rid of any residual 96kHz jaggies.
My trick for interfacing receiver to filter to converters is working great -
this is something I don't see anyone else doing. Very simple, but just a few
added components really cleans up the logic waveforms, improves jitter, and
greatly reduces coupled noise. Keeps the digital out of the analog. I've
never seen this talked about in any of the online forums. He he he, one of
the benefits of engineering other than audio circuits. Nothing like being
able to apply Shannon's theory to signals within HAGDAC. Someday I'll have to
list all of the enhancements I put into this design.
Also really helps to have the right test equipment. My special 1pF probe and
200MHz scope can really dig out the signals. The P6057 and 7A24 combo give
you quite a true reading of the actual waveforms without added loading.
May 2, 2005
-----------
I turned 45 today! Finally moved out of the agonizing age group of 40-44,
which is packed with elite quality athletes (I compete in triathlons). Next
race is half-ironman (is that like a half-kit?) in June; 1.2 mile swim, 56 mile
bike, 13 mile run. Aiming for under six hours.
Made some good progress on the HAGDAC today. Most of it up and running, was
able to lock onto the stereophile CD3 test tone and spit out a really nice
looking analog output.
1kHz square wave response
Goofed on the /invert input (logic levels are negative!) and almost fried the
$20 converters. Missing some parts, on order. Red wire bypasses PLL
reclocker, which I hope to work on as soon a parts come in.
HAGDAC proto
May 1, 2005
-----------
I'm experimenting here with putting a daily blog online. Going to keep it a
bit raw in both prose and appearance. This will be a place to post thoughts
on design, philosophy, issues, etc. that don't really belong on the customer
service forum.
Forum
Perhaps some insight into the trials and tribulations of product development
will offer some understanding into design choices and what's going on behind
the scene. Stay tuned.